What does it means Case Is Being Actively Reviewed By USCIS for my citizenship?? Applied 6 months ago

Yes this generally indicates that the case is in active review so you should receive correspondence soon.

Can I get married? While having a u visa pending.

Yes that should not be a problem as long as you have valid documents to marry.

How do I get a green card to my Argentinian 80 yo mom as a naturalized US citizen myself (and make sure she gets ACA insurance?

Best thing to do since you are ready to proceed is contact an attorney using Avvos search tool. The first step would be to begin consular...

I130 related?

The receipt means that they accepted the I130 as is but USCIS may issue a request for evidence if further documentation is needed.

Rfe after i485 interview based on marriage?

Likely a request for evidence of further explanation of lack of cohabitation with other documents that you can provide to establish your good faith...

About interview

Many cases filed years ago are taking years until the interview is scheduled. Contact the asylum office directly to inquire about your case.

What category should I put on my form I-765?

The filing category is C9 per the information provided.

Shall I call USCIS for my AOS status check?

No it can take well over 2 weeks to receive the RFE.

I-130 A application

Per I130A page 1: “If you reside overseas, you still must complete Form I-130A, but you do not need to sign the form.”

Leave this section blank and provide your I94 with the application.