i have 3 rainbows, been meaning to do a photo shoot with them, when i do i will post up the pics for ya!
they are great snakes, however mine are not as "handleable" as our ball pythons. i find they tend to be more like corn snakes in the sense that they don't sit still. they constantly are trying to run away.
and yes, they can be quite grouchy sometimes. i've been nipped in my face by a baby (no big deal, just scared the ever living daylights out of me!!). but for the most part they are pretty friendly snakes, easy to take care of. the humidity requirements are basically a non-issue if you keep them in a tub with a big enough water dish. i wouldn't recommend a glass tank for them, though.
i haven't noticed a huge color change in mine, but i'm going to have to look at some baby photos!