Well, I've worked a bit on the moving and I have it nearly figured out. Player's character wanders in the same way the one in Diablo does - it goes to the closest point that's available to place where user clicked. Camera also follows the main player like in the aforementioned game.
I have small problems with creatures following the avatar: I've released the Secretary and ordered her to charge at the player, but from time to time she'll pick random direction and cross any walls and go there. Dunno yet why's that happening.
So far, the game looks more or less like this.
Next on: Random level generation. For now it'll be just walls from holes, but later on I'll add actual walls.