No there should not be a benefit to either location.

If interview was canceled, wait for rescheduling.

You should be able to depart the US without issue but reentry will be the issue.

Yes the employment verification letter should suffice.

No this is not possible given your adoption.

Best to file under 5 year rule given timing of LPR status.

Yes it appears you are missing evidence to show you completed your sentence.

The date that the receipt notice was sent.

You should list her but she will not automatically obtain citizenship.

Yes this could be a viable basis for expedite request.