Hello~ my first post here.

Thanks for let me test the engine, I'll be posting all the suggestions I think on this topic, and will add a new reply to notify any changes.

A good idea is release some features as addons, some with ingame configurations, and other with plugin parameter configurations.

• Load any file stored in the Tileset folder (may read subfolders) [Feature that can be enabled/disabled].
  Being dependant of the classical Tileset Database is not a good idea when we're translating everything into a 3D environment since it limits the amount of graphics we can put on it, imagine wanting to make a well defined city with shops, different kind of buildings, etc, but the database only allows you to keep X graphics from A to E.
  
  By allowing us to load any tileset file from the folder, we can combine many things easily without have to photoshop a single time, just download resources shared by the community right on the tileset folder and enjoy, thanks to the ability of also read subfolders we ensure to not have a mess.
  
  It's important to not be a replacement of the current system, but as an addon for the people that wants more freedom and availability.
  
  However due stop using the tilesets from Database, we're losing some features, which would need to be added in the editor itself, which are basicallly a separate editor for the "Ways", Directions, High grass, Damage tiles, and Terrain tags, also I think is a good idea to still let us pick a Tileset entry from the database, so certain plugins that uses the notebox can still work (if them doesn't make compatibility issues).
  
  EDIT: Also, as for autotiles, a good way would be that putting a $ at the beginning of a subfolder name it automatically recognize these tiles as autotile ones, and ~ for animated ones for example.

• Expand shortcuts and let us configure them.
  I think that this is already thought by you chaucer, so I won't go depth on it :)
  But basically this would make your engine more fluent, so by pressing certain shortcut/hotkeys we can rotate the boxes, offset them X Y or Z, etc, basically improving the workflow greatly, and this would also allow us to better control the scale of boxes/textures and also increase its limits to more than 2.00

• Replace the cursor function of rotate camera with drawing capabilities, and make that to rotate the camera, we need to hold the press of a button and drag instead (like Shift + Hold Left click).
  The editor is really strong, but having to move by WASD and hit enter this make the map making much slower, if you do that the camera is moved by holding Shift or Ctrl key (or Right click which is more comfortable :) ), you'll allow us to draw by click, and if you increase the zoom speed and camera speed (found it right now in the parameters), we can just zoom out, rotate the camera, and quickly build the map.
  
  I think you know RPG Paper Maker (the free counterpart of RPG Maker) on Steam, if not, take a look on it, it can give you some ideas for your map editor :)
  
  If this is added, then the rest of suggestions can be done.
  
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• Quick "Square-Circle" drawing and selection tool.
  I think doesn't need explanation, if you make that we can draw with the cursor, then this could be also achieved :)

• Allow us to place custom collisions.
  A good idea, maybe quick maybe not to make, could be two ways to add collisions:
  
  1. Make that the texture itself has collisions (First starts with an auto-tile collision): ON/OFF button to trigger autocollision, plus, once it is expanded to work with independent textures, another ON/OFF button to see in red those textures that has collision.
  
  For now, as a quick measure, could be that instead of put collision in the texture itself, it's placed on the tile directly of where the texture was placed, at least until a pixel movement is added to make recognize texture collisions, so we don't need to place the collision later separately.
  
  2. Tileset Collision Edit mode: By pressing the button to enter in this mode, you can place the collisions like any floor texture, the tiles with collision are turned red, this is a very good feature which I experienced on Brow-Edit (a Ragnarok map editor), this give room to us to control accurately the collision on the tiles we want, first we make the map, then, we place the collisions. Also allows us to make secret rooms and more.

Okay, so now about the place where to add any new edition mode such as Collision Edit, Selection Tool, etc, I think that just adding a toolbar on top with these options as buttons would be the best way, it can be an horizontal command box perfectly with icons instead of words to make more free space.

That's all for now!

I would like to see a list of your work in progress too!
I'm very sure that you already thought many of my suggestions, but I don't find any WIP list :(

Thanks for the feedback! I appreciate the effort in putting this list together, some of these things are already planned, however some of them may not be implemented at for limitation reasons.

I'll go over these one by one. :) Just be aware, the editor will be one of the last things to get updates, I'm focused more on adding the remaining missing features of rpg maker MZ, as well as integrating support for MV. :x so these will likely be changes that come later.

Load any file stored in the Tileset folder (may read subfolders) [Feature that can be enabled/disabled]. :

this will more than likely not occur, the way tilesets are used, it's just not very likely, as it would drastically eat up vram, which if you have a decent graphics card, that's no problem, but lower end gpu's( and mobile devices ) will likely run into issues, and my goal is keeping this compatible with as many devices as possible, :( apologies for that, photoshop may be your best bet for this. :x

Expand shortcuts and let us configure them. :

I plan to remove the default rpg maker mv/mz keyboard input settings for the map editor, and integrate my own full fledged keybindings to speed up development process, but for right now, it may be a ways off. :x

Replace the cursor function of rotate camera with drawing capabilities, and make that to rotate the camera, we need to hold the press of a button and drag instead (like Shift + Hold Left click). :

This is planned, however I have not integrated picking yet, which is why I am also missing touch movement in the game itself( it is coming soon though ).

Quick "Square-Circle" drawing and selection tool. : 

This one is planned as well, I also plan to make auto tiles, actually automatic when drawing with a square/circle tool, so this will serve multiple purposes :D 

Allow us to place custom collisions. :

I will consider this, however I don't want to overwhelm the average user, creating 3D colliders can be a rather complex process, at the very best, I'm thinking of providing basic collider shapes which would be able to be scaled/rotated/ and positioned, similar to the mesh itself. 

On this note, I do plan to add vehicle specific collisions as well. :) but that will come after vehicles are implemented.