Honestly guy...relax. Talk of selling your mac is a little premature at this point. You are really adding to this snowballing hysteria going on this forum with all your worrying in multiple threads!
I had the same opinion until I just noticed this thread below
https://forums.macrumors.com/threads/506784/
"...Subsequent debugging indicates that the machine is misidentifying its NVIDIA GeForce 8600M GT card as the MacBook’s Intel X3100 card. This issue is known to affect at least 50 people - a group of affected users has formed a Google Spreadsheet in order to document and organize cases.
AppleCare is recommending replacing the logic board, which some have gone through with, only to have the machine return to an unusable state shortly afterwards. Compounding the issue is the fact that this problem has arisen only shortly after the expiration of the default warrantee on these machines..."
I never buy extended warranties, statistically they're a silly thing to throw money at because over time you'll come out ahead sucking it up and paying for the odd failure out of pocket. But when there's evidence something is truly wrong, a design flaw that alters the statistical balance significantly, then buying the extended warrantee is a given if you actually want to keep the machine for any length of time. With Apple Care being over 15% of the cost of my machine, I'd probably be better off just selling before the 1 year warranty is up and getting whatever is out at the time that doesn't have this issue. Suffice to say I'm none too pleased about that.
EDIT: Hmm...
https://forums.macrumors.com/threads/514715/