Just noticed it's possible to close a door with a button mid movement through said door... at the start of level 7 there is a room with 2 iron doors both can be opened/closed with a button one tile away from the door... if you move into the "open door" and press the button while moving it will close, I tried the same at the other door and then worked out there was no way out anymore as there are no buttons on the "inside" of the room...
I'm guessing there are other doors that using this method would lock you up as well...
This is great for those hardcore role playing characters who want to end up like Thoorum until the bitter end (that is if a mod adds starvation

)