TOWARDS LORDCRASH: Maybe the game isnt optimized the best way? I know that will make you cry because you love it so much and you have to defend it from EVERYTHING AND ANYTHING. But its just true.
If I recall correctly and perhaps I'm not. LordCrash actually had performance issues that were either corrected by a patch or a tweak he did. So he actually has been in the same boat as you. If I'm wrong with LordCrash, others have been in that situation and have worked it out, at least temporarily.
If one is over-heating, in the meantime, the best thing this game has for you is the FPS slider, if you are at least getting good frames you can cool your GPU some by lowering the mx FPS.
If nothing works for you, then we hope it is addressed soon, sucks being that guy with that game.