My rear main seal leaks...left hot spots all over my flywheel too. It's a good thing you fixed that leak, it eventually caused one of the springs on my pressure plate to pop; therefore, leaving me stranded one night at a red light...not fun.

Crazy thought...do you have another itr...or even gsr trans spare (as in, a shop or something that could let you try it out)...just to see if the trans has a problem or not. I'm just thinking of elimination steps here.