Hey man,
I saw your videos and I might be able to help you figure out the overheat problem with your Titanium PB G4. First off, like the Pismo(I assume) have you checked the heat sink for dried paste?
I would apply new Arctic Silver 5 to the core on the PowerPC processor. That should take care of your overheat problems, if that is the case. Secondly, When did this happen? Usually, if the heat sink paste it dried up and or the heat pad is worn these issues will happen. On my G3 500 Pismo(Now, G4 550) I had to re-apply new paste as my processor temps were getting high, but not as high as yours.
As for the other problems, I am sure someone else can chime in.. but be sure to check the paste to make sure its enough to cool the processors.
Hope this helps..
PPCMM