From what I've read “Thread.MaxProcessorCount” is broken and not working atm. It can't hurt to add it to your user.cfg, won't make things worse. You should use with the number of cores your CPU has. I have an i5 which has 4 cores so I would use Thread.MaxProcessorCount 4
Just check how many cores your cpu has.
If your computer is overheating and your FPS a dropping after 30mins of gameplay, I would suggest your GPU is overheating. It would not be your CPU. You probably have bad airflow (and/or alot of dust) inside your case.
Some of those settings your putting in your user.cfg are pretty useless (as in aren't even commands) and/or don't have that good of impact on FPS. I suggest just the following (pre Jan30th patch).
GameTime.MaxVariableFps 125 *set this one to 1 number above the max hz of your monitor (i.e 60hz monitor set to 61, 120hz monitor set to 121)
RenderDevice.ForceRenderAheadLimit 0
RenderDevice.TripleBufferingEnable 0 *only if you run with vsync off
PerfOverlay.DrawFps 1
Thread.MaxProcessorCount 4 *Number depending on amount of cores your CPU has 2,4,6,8,12
WorldRender.SpotLightShadowmapEnable 0
WorldRender.SpotLightShadowmapResolution 256
WorldRender.TransparencyShadowmapsEnable 0
Last three threads about shadowmaps, I would try running without them post Jan 30 patch (as these issues are supposed to be fixed now). If however you try with and without them, with them getting better FPS then keep them on.