Yes, this is my opinion, meaning that the engine is not overheating from what I read. In the context of: time period of 210, duration, fairly easy and quick cool down, summer temp, sitting still, not boiling over even after shut down and no known design changes since last summer or 10K miles. It is normal for those conditions and will not damage.
Whatever other areas you are speaking about are present in all trucks and their gauge readings, gauge tolerance/calibration/quality.
Yes the temp inside the motor can get over 212, that's exactly why the system is pressurized. The cap is designed to control boil up to a designed safe level of heat. It is a pressure relief valve. The steam release is a designed-in signal of overheat, if you didn't see the gauge, and protects hoses and radiators from blowing up hopefully. You turn off the motor ASAP.
10,000 miles can be considered a lot of miles on some rebuilds.
