Why is this 10pF capacitor reading 79pF?
The only way to be sure of a capacitor's true value is to disconnect it from the rest of the circuit before you measure it. Other components within the circuit could be contributing additional capacitance and other effects if you try to measure it in-circuit.

It's unlikely that you damaged the capacitor when soldering it in, non-electrolytic ones can usually take the heat without any risk.