1)Yes, that's ok. The two holes on each side are connected to allow for different footprints. No, you do not need to fill all holes.
2) if you bent the legs, it's all good. If you actually broke the ceramic part, you might wanna replace them.
3) It's rather unlikely you damaged the resistor network. You can measure the resistance from the common pin to every other pin.
4) What exactly are you planning to do?