MacBook - My poor macbook 2.0 Core 2 duo, but know I find out the problems..

Let's just say that is was a great deal for me, had an older ibook G4 1.0, 1.5RAM 250 HD that sold for $400.

I know someone selling his macbook 2.0, 4GB RAM, 80GB HD, DL-DVD burner, so I bought it for $480!!lol
It even has apple care till 8/2010

I have been having apps shut down like crazy, disk utility, safari, sys pref and etc.
Fan seems to be running at 6700RPMs all the time.
Also the top case is separating from the bottom.


But I know find out the bad things, all of these have been replaced..

Battery 11-29-07
Logic board 4-3-08
Logic board and superdrive 10-3-08
Superdrive 10-6-08

Now the new battery is running really hot and is deformed a little and i'm having problems with the super drive again.

What would you do??

If they replace it with a new comparable mac, will it have apple care with it??
As mine has a year + left on it as it sits.

If I take it in for repair, should I take out the 3rd party RAM 2X2 Kingston, will they shun me for only 512MB OEM apple RAM?

Does apple make a 2GB ram stick for macbook?

Thanks you really much for your time..

Take it in for repair and make sure to get the spec logged and a copy, so that if they swap it out you get the ram back.