A VAC Ban removal is not impossible at all, i've seen one of my old teammates got VAC Banned, he had a nice inventory with dragonlores and some marble fades m9 once, and after 1 week he was unbanned, it was due to some programs that was faulty flagging accounts and i think he got it removed automatically, because Valve can see how you got banned, so they removed everyone who got banned for that reason.