1) Effectively it was (not the skin, but the TAT probe. The highest temp rise would be at the stagnation point so one can be confident that TAT is a realistic answer for max skin temp).
2)
AFAIK pretty standard:
Q from pitots
S from statics
T from temp probe
Modified by ADC for position error. It's possible that ADC used beta inputs and I'm sure it used alpha inputs to achieve this.