Polishing question: stone/paint chips, hand polish and headlight

Hello all, I am polishing my car for the first time and I've got some basic questions for you, hope you will spend a few minutes to help me out, thank you!

1. polishing over stone/paint chips and dents: do I have to tape them over, or I can just go over them with my polisher?
2. for hand polished areas like under the door handles, which polish do you recommend? I have M105, SIP, PF.
3. to polish headlight/taillight, can I use a light cutting pad with PF?