1.you need a permit to replace the panel.

2. if you only replace a small portion of wirings in the house, you might not be in trouble without a permit. It all depends how the local inspector handles these things.

3. add grounding typically doesn't need a permit, but you need to know what is the right way to do it. (the size of wire, what metal, how deep, etc.). 

Just remember you are liable to anything happened to the house.