Yes, you may request visa appointments at several US embassies at the same time, if practicable and accommodated.

The grant of a visa is a privilege not a right. You are not obligated to use a visa if you so wish. Good luck to you.

It appears you have abandoned your LPR status. There may be remedies. I recommend you work with an immigration attorney to review your next action.

It is best to discuss fees with the immuration attorney you retain for your case.

Your inquiry is a political question. In general, changes would be expected.

Yes, a person can buy property in the US under my father's name.

It may be a good sign because your status is not denied.

USC may sponsor parents for US permanent residency. File I912 to request for fee waiver.

Yes, report the incident to immigration. Good luck!

Yes, one can change status from H4 waiting for approval to H1b.