You are not legally required to meet with DHS.

Yes you should be able to travel without issue but can obtain the I551 stamp for reassurance.

A review of your criminal history must be made to better assist.

Yes while possible only advisable if there is something better and pending.

Yes you do not have to participate with the DHS inquiries.

Your case should be reviewed to better assist you. Good luck.

It shouldn’t present any issues but generally all documentation should reflect current legal name and be accurate.

Yes it is very normal for delayed biometrics or they may be waived.

Yes you can file the appropriate paperwork with the immigration court.

A review of your record is advisable.