Downloading the latest drivers for the video card off of Nvidia's site is a good idea, gives a performance boost. You can overclock it a bit to boost performance further.
I'm guessing it restarts because your video card can't handle the set graphic settings, but I don't understand why it would launch in safe mode though.
The only thing you want to uninstall are the old video card drivers, and you know if you installed everything if you installed the latest drivers and it works
For that card, because it's mid-ranged, 1024x768 is probably a suitable resolution, but you can choose any resolution that your monitor and video card offer.
The 16 and 32 "things" are the texture bit depth I believe, and 32 is obviously better and more detailed, however it may compensate some performance when activated.
The card you selected is a good mid-range card, decent for gaming, although I would of spent the extra $25 or so and buying the 6600GT, which grants GDDR3 memory and much higher clocks. I can't compare the 6600 to your previous card, because I don't know what your previous card whas :P But if you upgraded to the 6600GT, you would probably notice somewhat significant improvements, depending on the game. Your processor and memory are also important, because if too weak, they could bottleneck your video card. So I'd advise posting your processor and memory information.
Anti Aliasing is an option that can be activated that basically makes everything appear cleaner , more crisp and defined. It basically smooths shadows or small things in games. Here
is an example.
Hope this answers your questions, if not let us know