Well BFG wouldn't really be able to help you, so queueing for that longs probably a waste of time
All they'd be able to say is that you should send the card back for checks, since its probably not a problem reported alot.
Try doing what Arrizx says, and if that doesn't work, it could be something more serious.
I'm guessing when you say the screen flashes, it sort of goes blank and then comes back? If so, thats pretty normal.
Though the mess ups in games, that could be pipeline related, if its producing dots/pink artifacts, etc that shouldn't be there.
if its been doing it from the start, this could be the case.
Other issues could be overheating, yes, since thats a very powerful card you have there. Without apporopiate case cooling, like with any card, it'll just overload and also cause the errors you've described.