While I like this in theory, it's too broad a topic to put a sticky on. There's no way you'd be able to follow a coherent thread.
My suggestion is to go ahead and post balance issues as they come up (I recently posted one about whether Assassin Pretenders were or weren't balanced and what factors came into play there) and let them run their course. The game's too complex to have a single balance thread.
Just thought I'd respond since this topic had gone unloved for a while.
