Whats the big deal, dude? You have 2GB RAM like me and I notice no difference (or 3dmark score) with running CCC. Like all things PC, many people who complain about new games, etc, complain cos their PC is inadequate -- so don't let naysayers discourage you. Just run CCC and you'll be perfectly fine.
You CAN run Tray tools simultaneously, as far as I know....though that would be too many programs to do the same thing.
And yes, you need CCC for crossfire.