UI aside, the whole game is suppose to be playable with full keyboard or gamepad, mouse being an afterthought. It seems you found a bug with the battle UI.
I screwed up enemy balancing last minute coupled with the encounter rate bug makes fighting anything painful. The idea was better/more equipment boosted accuracy at the cost of speed. But it obviously wasn't enough accuracy, and speed is a determining factor in running. So the better gear actually makes the game harder.
Bonfires were suppose to be the checkpoint system but was cut due to some dubious programing. Instead it just reloads the floor but keeps your current status. In theory you could grind up duplicate items and win. In practice you burn all your healing items and softlock.