I agree with Knight that first I would check the starter valve synchronisation, that should also steady-out the fluctuating idle. After that maybe the TPS sensor has a doubtful connection? I know the 6th gen has extra O2 sensors that the 5th gen lacks, maybe these need to be checked or removed? Also, I may have read that the PAIR system can affect the O2 readings as well, so you could try a quick and dirty PAIR block using a marble in the supply hose and see if it changes.
What you describe matches the temperature dynamics of my 5th gen. The last time I rode the 6th gen it was in the low 90s ambient air temperature, the bike ran a consistent 214 on the road at speeds of 70 and 80mph but cooled to 209 once I slowed. My 5th gen is just the opposite. If I am running fast the temps tend to drop with all the air moving through the radiators. The temps start to rise when I slow down. Will the 5th gen wheels fit the 6th gen? I took the wheel with the ding to the shop where i work. The service writer said he had a guy that could fix it so I am going to give that a try before springing for a used wheel. It's not that big a dent really.