Help, I'm too cool!

[docbob]

Is TIT lean of peak or rich of peak? Slightly lean of peak is good for the engine and results in lower CHT.
A rough rule of thumb is that an oil temperature around ambient deg F plus 100 deg F is good. Seems that at 12.5 you might even be a little higher than this. It is pretty hard to imagine how running at these temps could harm the engines. I (normally aspirated) have been looking at CHT's around 350 for 18 years.
Shock cooling during a careless let-down causes lots of damage. The lower the starting temp, the lower the shock-cooling effect. Adequate oil temperature (and, thus, flow) before full power application for takeoff is important. So a good warm-up is smart.
Bottom line: seems that you are well within the green arcs.