Can I post my TPS application up to December 21,2015 or it has to reach to USCIS office by that date?

It should be received by that day. file ASAP.

can i485 AOS be transferred before VAWA i360 adjudication?

I think it is a repeated question. Don't read too much into USCIS updates. Just wait for the decision.

Is it any help to file for him since hearing is set at 4yrs, and if so What are the forms I need to fill to file for my spouse?

I am not sure I am right here, but if I understood the situation correctly, your husband would need to ask the judge to terminate his conditional...

I would not bother with changes, the difference is not significant.

How long was I over stayed?when can I re enter the us?

Clearly, you need to meet with an attorney as this forum is not a place for a specific legal analysis or advice.

You should be able to do it. Good luck!

Can my friend go to mexico a few weeks before her interview

You can if you feel confident you will keep your appointment...

Can i get unemployment benefits?

As a permanent resident, you can file for unemployment, however, you may not get it if you are fired for a good cause.

After I140 is approved, do I need to start working with Company B Immediately?

You should speak with your attorney. A different company can sponsor you for a green card, but usually this is also the company that "transfers"...

Will I have any problems to apply separately such as delays on my green card?

As long as you have proof of your status, you will have to submit a separate I 485. Good luck!...