You should contact USCIS to inquire. It could simply be a technical error.

You will likely end up in the F2B category given your age and the timing of the petition. It will take about 8 years for you to immigrate through F2B.

Your spouse will need to attend an interview at a local field office in the U.S.

Your mother is not qualify for the N8 category. She will need to apply for a B1/B 2 visa.

It depends upon how involved you are in the rental process. Passive income is fine.

You should contact USCIS to inquire about what is happening.

A passport application can be denied if the giver determines you are ineligible.

No. Your F-1 OPT EAD will remain valid so long as you comply with the conditions of your status. If you start working on the DED EAD, you would...

You need to be patient. If the consulate needs anything further, they will contact you.

It is not advisable to simply overstay one’s status. Your mother should comply with the terms of her tourist visa.