When using SetScale() on an object, I really need to know how to make the object's collision information match it's new size...in particular, I want to be able to make a spell that shrinks the player to let him go through a tiny opening in a wall to access certain areas in a dungeon...but when I shrink myself down, my collision box is still normal sized, and when I make myself huge, I can walk right through objects that should impede my movement.

No idea, but I'm just reacting to say that it sounds like a brilliant idea with lots of potential for all sorts of stuff.

Really if this works these sorts of scripts should be shared on the wiki so more people can use it (with approriate recognition of the maker) in their scripts.
(just like basic teleport scripts which a lot of people are reinventing daily.)