Will the power supply be damaged if pins 7 and 8 are accidently reversed?
There should be no damage.
What is the impedance of pins 7, 8, 9, and 10?
Pin 7: 11k ohm
Pin 8: 100kohm during normal operation
Pin 9 and Pin 10: 10k ohm
Is there any protection on the pins?
All interface pins have protective diodes and series resistors.