Why can't we rerate members? Say we think somebody is really helpful, and later they turn out to be full of steam(for a lack of better worD) why can't we change their rank?

Because the software doesn't work that way.

Take time judging someone before rating them.

Can't somebody change their mind after a few years? Say somebody isn't who they thought they were when they first got to know them.

i agree... i would rate ian a 5 now... but actualy rated him a 3 back when i thought he was an idiot.... and he only got a 3 because he started xoc.