Yes you may do so if eligible otherwise.

Yes you may request a consulate change.

More information is needed about your particular case. Consult with an attorney in private for guidance.

The CSPA appears to apply in your case but best to have review with an attorney.

It appears the answer would be yes for those questions.

Yes the signed and notarized statement should be sufficient but USCIS may want to confirm the period of time between submission and interview.

Yes the signed and notarized statement should be sufficient but USCIS may want to confirm the period of time between submission and interview.

This should definitely be corrected before filing an application for permanent residency with USCIS.

No this should not matter in terms of timing.

This is due to Covid backlog which will take some time to resolve.