So i had just recently bought a Asus G72GX and i am having problems with it and i need someones help with this

here are the problems i am having
1. Shutting off when it reaches a a certain temp. Like it would shut off when it gets to about 97 Degrees Is it over heating?

2. I cant get games to run with my graphics card. I had just installed bf3 an assassins creed and when i ran both of em they didnt run and my hardware meets the requirements able to play it.

, Cant find any wifi to connect. I went into the Windows mobility center and i couldn't turn on my wifi adaptor. the wifi switch on the side of the computer is on but it wont turn onso i have to use a ethernet cable to actually be on the internet/
4. High temps & fan noise. when i first booted up my g72gx it was silent but when i used it for 20 minutes the fans started up and when i checked the temps it was at 78 degrees
5. It crashes when i open up steam and i cant seem to fix it

So would anyone be able to help me with these problems? Im not this smart when it comes to these things