1. Yes, you can file a petition under section 12 HMA seeking annulment of your marriage owing to his impotency before the family court in Chennai.
2. No, that has nothing to do with the quash of 498a, that is different crime, you can always object to his quash petition by filing a detailed counter when you get a notice on this from high court.
If your advocate is not guiding you properly you may change the lawyer.
3. It is rubbish, dont be misguided on this, nobody can misuse such things, it is not maintainable in law, dont believe such rumours.
4. Tell your father to not to accept them as true when deposing evidence in the witness box in a court of law, in fact this cannot be taken as evidence to prove their case, you can always demand your jewels.
5. You lodge a criminal complaint with the police under section 406 IPC seeking return of jewels, they will do the rest of things.
6. You were planning to file annulment petition and not divorce petition, if he ignores and do not appear before court after receiving notice then you may get an exparte decree in your favor.
7. This is a strong case for annulment, you file in this provision of law alone and that too before completion of one year of your marriage.
8. He cannot file MCD anywhere without you signing the papers, because it is a mutual consent divorce to be filed jointly, hence you need not be worried about it.