1. The police or her lawyer cannot issue such threats.
What is your lawyer doing than to counter such threats posed by them.
You can issue a legal notice to the concerned police to refrain from indulging in such illegal activities, if at all they want relief, let them approach court instead of indulging in such illegal acts, or else, you can warn them that you will approach human rights commission against the police as well as the lawyer for their excesses.
2. As I had expressed that you cannot transfer the criminal case to other state except under extra ordinary circumstances, you may take proper legal action as per law instead of getting scared by such acts of cowardice.
3. That depends on how you challenge her in the trial proceedings.
4. Yes, you can file an application before high court to remove the names of the relatives from FIR.
5. See the answer to point 3 above.
6. Yes, you can file it.
7. If the place of marriage or the place where you both last resided was in Delhi then you can file divorce case in Delhi.
8. If yes to the above answer.
9. Your mother can file DV case against her and not you.