To keep from cluttering my issue and bug report post I decided to make this post for submitting my own suggestions. This is a list of ideas I have, within reason. I have no idea what is planned so some may be concepts already in progress. These are, in the end, simply suggestions and not expectations. This first set of ideas will revolve mainly around the player and some basic item ideas. I’ll make more comments on this post to offer different types of suggestions every so often, hopefully giving you some inspiration. I'll try to tackle some bigger issues you've posted about, such as stats, when I have something solid to offer.

• Dual wielding for weapons and grimoires if casting and weapons are given separate stats for their use. Equip slots would likely need to be added for ease of use.
• Two-handing weapons and grimoires. This would restrict you to a single equipped weapon/grimoire. The cost/drain of two-handed items would be reduced, and any stat bonuses they grant would be buffed, since you’re sacrificing the use of another item.
• Summoning Grimoires. These would summon a certain type of enemy to fight alongside you. The first summoned creature would be at the Grimoire’s listed summoning level, and any additional summons will be at an increasingly reduced level until reaching the limit of active summons, or a higher level summon dies/despawns.
• Allowing the player to punch by clicking while their hands are free, and pick up / hold onto stuff by holding the buttons, maybe even allowing for climbing. This would drain energy as expected, with a light weapon cost per punch, and over time drain while holding on. Arm strength would also buff unarmed damage and climbing/carry efficiency.
• A bit of a crazier suggestion, but the option to equip items in the player’s hand-feet. They wouldn’t be actively equipped, but by pressing an input, like “r”, the player would start walking on their main hands and bring out the items equipped to their feet. Items equipped in each slot hand wouldn’t be held while the other mode is active, but wouldn’t be moved into the inventory when changing modes, just kept in their slots. I hope I explained this well.
• The ability to gain some form of ranking with a “Wawsp Queen’s Head” by consuming creatures. The head would have a favored meal listed, and drinking that type of enemy would make the head like you more. Possibly granting the head the ability to partially heal you by drinking enemies. Other sorts of head items should also have some kind of abilities to differentiate them, considering they take up different amounts of inventory space.
• The Dream Eater’s mask dropping after you defeat the boss, like the Wawsp Queen.

Here are my thoughts on each of the current stats. I’ll make a post on possible fixes or changes when I’ve sorted something out. If anyone wants to offer their own takes or corrections, that would be a huge help since I’m not perfect.

• [Health Max]: A bit of an odd stat. During normal play it can be a bit hard to tell what sort of damage you can handle (Which is made even harder to judge due to physics based damage and a lack of I-frames), since the bar is always the same no matter what your health is, and with how easily you can avoid damage it seems at least generally fine. Due to it scaling exponentially it may cause issues later on, but not sure yet.
• [Health Regen]: Underwhelming if not outright pointless. The difference between max level Health Regen and base Health Regen isn’t really worth the investment unless you have a juice surplus. You seem to heal at a percentage over time (meaning that the amount of health you recover is reliant entirely on your Max Health in order to be worthwhile) and it still takes way too long. I was surprised, because I thought it was better during gameplay, but during testing I figured out that drinking enemies heals you faster, and I drink constantly.
• [Energy Max]: I did several tests. Primarily with a 1.0 scale Rune Longsword at 0 Arm Strength, the Tiny Sun Grimoire, and flying. Both aiming a sword and moving while flying seem to drain it at about the same rate, and with max energy give around 6-ish seconds(?) at maximum, and 2-ish seconds at default. (Also I’m pretty sure that flying drains faster if you hold more than one direction at once). Tiny sun can fire 5 times with no points in it, and well over what felt like 12 at max, it was hard to tell. Energy Max itself doesn’t seem to be an issue, it’s the other stats that depend on it.
• [Energy Regen]: Like Health Regen, it’s percentage based and I found that drinking enemies increases your recovery speed (though it was a bit harder to tell so I may be mistaken). The min and max regen speeds aren’t too crazy a difference, but are generally nice, way better than how Health Regen felt. Both Energy Max & Regen are a lot tamer than I originally assumed. I honestly feel like the default Energy Regen speed is too high, while the max feels fine.
• [Jump]: The worst stat and feature of the player, and the stat you don’t want to see items buffing often. Just flying is a better escape tool, since being ragdolled on demand leaves you pretty vulnerable unless you have a Grimoire (which is required with the way things are currently set up anyway, so meh) since you can’t aim ranged weapons while ragdolled/flying, and any situation where you’d be using melee with a jump is overly risky since you’ll keep colliding with the enemies more and more the higher the jump stat is (with Max Health and Jump a level 0 Stroll Fiend took out about a fifth of my health due to simply jumping into it). The only use it has is making your initial takeoff speed faster, since you always jump when you start flying off the ground (but if you jump and then start flying you’ll be slowed down too much to get any benefit).
• [Flight]: Flight is almost too good. Early game you only had to worry about Frolgs before the terrain update added early versions of biomes. Now you never really encounter those until you're off exploring the Wilderness. Other enemies can be very easily avoided at pretty much any stage of the game, and after the first boss you’ll never be touching the ground anyways. Even Wawsps, the only average flying enemy, are too clunky to pose a threat in the air. This is more an issue with the threat level of enemies and how stats are easily able to be cranked up than flight itself, otherwise it’s probably fine as is?
• [Move Speed]: Without some sort of sprint, default walking speed is painfully slow. That’s fine for the opening area, but once you get to the graveyard onwards you’re going to start feeling it. Since even base flight is better than walking, you’re automatically motivated to only fly in order to get around (and like flight it also has the issue of moving you faster if you hold two directions at once). Max Move Speed feels slightly slower than default Flight, however it costs just as much to max out as Energy Max/Regen, Arm Strength, or Damage! All to be just slightly less good than default Flight. I am however aware that if your Move Speed is too high you won’t walk and will just instantly ragdoll yourself if you try to move. If that problem could be lessened, I think the current max Move Speed should become a default sprinting option, if not slightly better than the current max.
• [Arm Power]: Tested with a 1.0 scale Rune Longsword and some larger weapons at various Energy Max levels. I don’t think Arm Power does anything, I couldn’t tell the difference at all no matter what I did.  It was clear that the scale of the weapon was changing how quickly it drained, but Arm Power wouldn’t reduce that drain rate at all? I tried a bunch of things but no results I could get with the naked eye. I spawned an item that gave almost +1000 Arm Power only and NOTHING changed. I can’t tell if I’m just bugged or there’s something that you need to check, because I couldn’t get any results.
• [Damage]: Damage was a bit too difficult to test. I could tell the stat was working at least. I can’t exactly tell by how much, so for the moment I won’t judge it too much, since the main issue with damage is that it’s way too easy to get higher level items to drop early in the game. Some playthroughs I’d end up with level 20 items dropping from the crates in the starting area!

Alrighty here are my stat suggestions. Probably going to slow down a bit after this, I feel like I’m kinda overstepping a bit with all these posts. Hope some of this helps in some way. Note that these are unrelated to any existing suggestions, just my take, so they may not align with current plans and are likely irrelevant outside basic suggestions.

• [Leveling]: Currently it’s too easy to dump a ton of points into key stats right away, and then you’re pretty much set after a certain point. I suggest a “Juice Saturation”. This acts as a Level for the player, which gates how many stat points they have access to and how many points they can dump into a single stat. Juice saturation would be progressed by draining the required amount of Juice at fountains. For example Juice Saturation 0 would be the default, and you’d advance that at the fountain to Juice Saturation 2, giving however many points and a max stat level of 1, and so on. Additionally I think Batty should show up when you reach a certain Juice Saturation, instead of strictly drinking the Good Juice.
• [Juice Max]: This stat (which could be Juice Max, Juice Capacity, or whatever seems fitting) would influence how much Juice you can carry at once. Currently it’s very easy to gather massive quantities of Juice, sometimes to the point of scientific notation not long past the Clog. Default capacity would definitely be something over 100, and could be tweaked to get the best feel.
• [Health Max]: Health is currently a bit hard to conceptualize. For now I can’t offer a change to how it functions, but more how it’s displayed. I think the default health amount should be shown as a bar with 1 unit (With each unit being a certain amount of health for ease of understanding), and that bar is divided into more and more units as health increases. Once it reaches the point that it looks like how it currently is, the bar should get longer up to a certain point. This should hopefully make it easier for a player to understand how much health they have.
• [Health Regen]: Regen speed as is, isn’t reliable. I suggest that after taking damage, Health Regen is paused for a second, and then steadily increases in speed up to some max regen rate. Regen also shouldn’t be as reliant on your Health Max in order to be effective. In addition to the percentage, which can frankly stay at the current max, you should regen a small flat amount bit by bit based on how many points are put into this stat. This would make Regen a lot more useful at lower levels when you don’t have as much health to work with.
• [Energy/Other Max]: The energy and any additional bars should also get the same visual changes suggested for the health bar. Aside from that, I think there should be two bars. The current energy bar, used for swinging/firing weapons and sprinting (if you add sprinting), and a magic stat of some kind called something like “Focus”, which would be for grimoires and flying. I don’t think these should drain Juice.
• [Energy/Other Regen]: As I said in the overview, the current max regen feels good, but the default should be a bit slower. Drinking enemies probably shouldn’t boost the regen rate of these, if that is how it works.
• [Move Speed]: The default walk speed should definitely be improved by some amount, and if sprinting is added this stat won’t really be needed. It gets harder to control at higher values, so having a decent set walk speed and faster sprint speed would be fine.
• [Jump]: Another stat that should probably be removed and replaced with some sort of dodge that’s easier to work with and has a solid use for avoiding damage. This “Dodge” stat would reduce the Energy cost of each dodge.
• [Arm Strength]: I hope the bug I found that makes Arm Strength do nothing is fixed. If it’s sorted out I’ll evaluate it a bit, but an addition I would have is it should reduce the cost of sprinting as well if you add it, since your legs are arms too.
• [Damage]: I suggest splitting this into three categories of damage, Wack, Bam, and Zap (For Melee, Ranged, and Magic/Status effects). This would limit the excessive leaps in power you can experience in the early game, and let players focus more into certain builds (Making the level of item drops less disproportionate would also help make these matter more, since right now it’s super easy to get really high level weapons in the early game, as I said before).

I was informed that Arm Strength increases weapon swing speed, and not the rate at which swinging weapons drains energy like I thought it did. So not bugged, but it is a bit redundant having a damage stat and a stat that makes melee hit hard, since it is physics based, which is probably one of the reasons for the stat overhaul, so that just falls into my damage suggestion, which was like what was said in the overhaul post anyways. What Arm Power currently does should be what a melee damage stat does in addition to a slight base damage buff.

I wasn't happy with how my stat suggestions turned out. I promised to offer something solid but I failed to even properly test the stats, so I have no clue how accurate my suggestions are, and felt I may have been a bit harsh. I'll stick to ideas centered around additions less integral to the game from now on. I'll make a post about some hopefully fun additions sometime soon. Sorry for any issues so far.