If your wheel is not in the list you still should be able to choose just 'wheel' and enable force feedback manually. But it could be possible that you first need specific drivers.
As stated above, install mods one at a time and try whether it runs fine. Too many people have experienced problems, not knowing anymore what mods they installed since it last worked.
Add-on tracks come in compressed format, so you'll need to uncompress the archive first using, for example, 7-zip or WinRar. Usually, you'll then have a folder that bears the track name which you then copy into your GTR2/GameData/Locations folder. Sometimes add-on tracks are packed starting from the GameData folder, so when you unpack them you'll get a GameData/Locations/<trackname> folder tree. You can copy this whole tree to your GTR2 folder, or copy the <trackname> folder out of this tree into your GTR2/GameData/Locations folder.
If you have set all graphics options to max in the GTR2config utility and in the ingame video options, there's not much more that you can do. The only thing left is setting graphics quality options of your graphics card through its control panel. Enable AA (Anti-Aliasing) and AF (Anisotropic Filtering), and play around with other options like multisampling or supersampling to see if you like the improvement and if it doesn't impact performance too much. AA and AF should be set in your video card controls, not in the game (GTR2config.exe).
What video card are you using?
Oh, and if you're running a high-end PC and get >60FPS all the time (assuming that you're using a 60Hz LCD screen), turn on VSync in your video card control panel. When you do that, also enable triple buffering. You'll need a program like Direct3DOverrider to get this done for D3D games, check this thread