Applying for a marriage green card throught a marriage with LPr

Her priority date mst be current before she can file I-485, if you a a permanent resident.

Co-sponsor alternative solutions.

You can use qualifying assets instead of a joint sponsor. The assets do not have to be in the US.

I have an approved I-140 from my past employer whose PD became current. Can I file I-485 using that I-140 at my current employer

Suggest you consult with an attorney.

If I work full-time in the US on a TN visa and I receive a contract offer in the US to work part-time, what are my options?

OSuggest you consult with an attorney.

Can i sue my previous lawyer for malpractice?

This question is unrelated to immigration.

90 Day early Filing for Naturalization and Interview Date

Doesn't matter to when the interview happens. They know when your five years is over and will have the ceremony at that time at the earliest.

H1-B: My H1-B visa has been approved and my status will change in October. Can I change my job and employer already?

I think you want to know if your next h-1b will be cap exempt. Best situation is for old employer to revoke no earlier than October 1.

I-130 FORM PART C- I AM GONG TO APPLY FOR MY MOTHER , SHE IS WIDOWED - SHOULD I STILL HAVE TO MENTIONED HER DIED HUSBAND.

If any question asks about your mom's husband, such as her G-325A which is required for her I-485, you must answer truthfully.

What are my options now?

Try to find another H-1B job ASAP. Even if you have a gap n employment, a god attorney might be able nonetheless to get USCIS to overlook the gap....

Your question is an employment one, not immgration.