Mac getting very hot while watching flash I'm running OSX 10.7.5 on my Mac computer (desktop, not laptop).

I have just been watching some Starcraft 2 stream from Dreamhack (in flash) when I noticed my computer was getting pretty hot. I installed some temp. monitor which showed the GPU was reaching nearly 70 degree celcius. This seems like a lot. 

I was viewing flash using chrome. I normally use linux and I know there are different versions of flash there, some better than other. Are there any wellknown problems with chrome and the stock flash plugin? Should I be using Safari? Should I install some other flash plugin? Or should I just totally avoid using flash on my Apple devices?

Thanks.
Flash has many problems, including making your computer run hot.  I have an older dual quad core i7 iMac, and Flash does that to my computer too.  It's also a large security hole.

I'd recommend removing flash completely, and when you need to run it, do so using Google Chrome.  Chrome has a sandboxed, often updated version of Flash. It won't solve the issue with it taxing your system, but it is a bit more secure.  

To answer your questions at the end:
1 - Chrome works fine - Flash is the problem.
2 - For Flash, I'd say use Chrome only, and leave Safari out of this.
3 - Chrome provided Flash is probably your best bet
4 - I avoid Flash as much as possible, but I do love me some Google Street View.  Gotta use Flash for it.

Good luck.