The AI generally decides that the outside is dangerous because that's how its described, and it's true to some extend, I've noticed it stops bothering you about it once they add a few adjectives in their memory about your character that indicate that you can defend yourself, in a few cases just having a dangerous weapon is sufficient for them to stop, because they know you're well armed.
Combat is quite simple, the key you need to press is actually the direction of the monster that you're attacking, it's contact based, if the monster is to your left, press left, if it's up compared to you, press up, and it's the same button for parrying.
You can turn off parrying completely in the options to have it autowin if it bothers you so much, I personally find it rather easy and simple, unless you get stuck between 3 bats affecting you in turn by confusion, which combined with the fact you need to face the enemy to hit it can cause some issues, but personally I rarely ever die in that game even against the fireball chucking zealots of the swamp temple.
The slow debuff is annoying, but all it does is make you waste time, and that's what's really dangerous, bring sticks with you at all time so you can make a firepit and a torch, explore the Flooded dungeon as soon as you can to find equipment and make money, preferably try to get your hands on a scroll of weightlessness and enchant your ring with it, inventory can be a pain and being overweight is your greatest enemy.
Walking after midnight without light and sleeping in the forest is the actual danger, because then shadowy figures spawn seemingly at random and make you go insane unless you have some equipment with devouring on it, and even then you'll be chugging potions, so bring a tent and lantern with you.
Always keep a few healing and cure potions on you, either make them using an alchemy table or buy them from Rosalyn.
Once you've done that, try to get two pieces of a key and go to the Fortress dungeon, and all you need there is to find a bomb.
Once you got that bomb, you can then go to the swamp dungeon and use it to enter, and by then, any equipment you find in chests can have ups of 10 defense, making the whole combat system a joke.
I can kit out a character in less than 2 in game days because I know exactly what to do and where to go, the combat system is fine.
I agree about the branches though, I find it quite annoying, and sometimes ironic our character gets stuck by something that shouldn't be any bigger than an inch and having to collect then throw them constantly.
The reason you were walking slow was probably exactly because of the overweight mechanic I was talking about;
If your character has exceeded their weight limit (number in inventory) you get a debuff (bag icon upper left of the screen) that doubles the time it takes for you to take a step compared to other NPCs, and quarters it compared to a deer/ rabbit. If you exceed it by twice that number you become immobile, don't do that.