I feel sorry for you but you never answer the questions that really need answering
you need to KNOW
what JETS you have and what the plug looks like when you are experiencing the stuff you say like:
smooth but low on power
and the no start issue
sorry but its really hard to help when you never answer these things...
you need to do plug chops
100c with oil cooler is about perfect...nothing worng there, oil MUST BE at boiling water temp or else you never rid of the humidity in the oil after shutdown and that is bad
my riding temps with the mikuni is about 120c all the time...or about 250f and it takes about 15 minutes of riding to get to that temp, maybe a bit more...