8800 GTS + VGA Cooler?

First off, here are the specs on the rig I just built:

Case: Cooler Master Centurion 534+
Motherboard: GIGABYTE GA-P35-DS3R
PSU: Corsair 520HX
CPU: Intel Core 2 Duo e6420
Cooling: Arctic Freezer 7 Pro + Arctic Silver 5
HD: Segate SATA 320 GB
RAM: 2x1 GB Patriot DDR2800
Graphics: EVGA 8800 GTS 320
Monitor: Acer 20"
+ extra cooler master 120 mm front fan

This is my first build and nothing is yet overclocked as I am waiting for the Arctic Silver 5 to ."settle" I just started playing F.E.A.R. on max settings at 1024x768 resolution and the game was running fine until I got a blue screen which then turned black, and then my monitor told me that the "input was not accepted" or something. I understand this to mean that the video card shut down to save itself from overheating. Apparently I need to install RivaTuner and crank up my fan as well as alter the Nvidia shutdown threshold.

However, many threads dictate that the 8800 series runs hot, and I am wondering what temperature the card should never go past, as well as whether I should install a 3rd party VGA cooler. Will leaving the fan at 80-100% shorten its lifespan? What temps are safe for the card? Thanks in advance.