HIs statements, plus his affidavit of support, should suffice.

It depends on the basis for the waiver. Perhaps six to twelve months. It may be possible to adjust in the U.S.

No, if you are not in status, you need to get your H1b overseas.

Generally it is possible for someone who is denied naturalization also to be subject to removal from the U.S. I do not see how that would apply to...

The dependent cannot be approved unless and until the principal is approved.

USCIS will go by what the official document says and not by your explanation to the contrary. You can try to get a new marriage certificate but...

You need to be the sponsor. Your friend can be a joint sponsor.

No, generally one cannot file for naturalization if they are not in the U.S.

Unless there is an issue for your continuous residence in the U.S., you are permitted to travel overseas while your N-400 is pending.

The short answer to your question is no, with very few exceptions, nonimmigrant visas do not require any medical exam. However you may be required...