Processing time for interview after the NVC complete ?

It really varies from embassy to embassy and also the time of the year. I would say at anywhere from 10-30 days at minimum.

How long is the process of I-824 petition for my husband

You can send an online inquiry to the USCIS and they will respond to you with a status in 2-3 weeks. You could also hire an attorney to get to...

Travel to canada with Green card

You will need a valid passport to re-enter the country.

H1B transfer from comp A to comp B,

Yes, you are required to go work for company B after your transfer.

Hi, my student visa been canceled and my I-20 is closed by March 2, how many days do I have to get my new I-20 into the US?

The grace period is 60 days, however, you may want to try to get it sooner than that.

What is the next step to do, after having %100 surety about CSPA eligibility?

As the process can be tricky and lengthy, you should consult an immigration attorney to guide you through the process.

Our F3 dates are current, can a sub beneficiary (spouse of main beneficiary) - file I-864 for principle beneficiary ?

Yes, it is possible for you to do so.

How do I prove to USCIS that they already collected my I94?

You can file a form to receive a replacement.

Yes, you can register an LLC. However, you wold not be able to sponsor your own E3 visa.

I currently hold an L1 Visa. Will this visa be marked invalid if I apply for a J2 dependent visa?

No, you can only hold one status at a time.