Is GTS even worth the time then? And how "unlikely" is it for pokemon hacked to damage my game? And would it even help if I try to get rid of the chimchar now that the pokemon is already in my game?
GTS is generally a dump, but there's always the possibility of finding that needle in the haystack. You're better off just using our Wi-Fi forum though.
As for the Chimchar, it's almost certain to not damage your game in any way. I've never heard of such damage being caused by what I can only assume is a legitimate hacked Pokemon (a Pokemon that has been hacked but is still within the confines of the game) but it's just one of those 'cover your ass' things.