Is there a way to continue working part time for the previous company?

(1) now that premium processing has been re-instated ... do NOT start working for B with a mere receipt. (2) have B mention that there will be...

Whats the best way to get married?

Have him apply for ESTA. If approved, it shouldn't be a problem for him to enter the US ... get married .. AND RETURN to the UK. The FL...

No, that is NOT permitted ... unless your DSO agrees to give you work authorization.

I agree with Mr. Behar: You are already on H-1B ... go to work for the company that 'owns' the H.

Actually, you didn't need to bridge that gap when an F-2 to F-1 is pending. Talk to an immigration lawyer, you've been making multiple mistakes.

Can I use old (2011) birth certificates from China (no longer a citizen) for my adjustment of status application?

Please explain what you mean by "(no longer a citizen)"

My re-entry permit expired as due to covid my flight which was prior to the expiry date cancelled. Where can I email to inform?

Where are you? When did you last leave the US? When does your greencard expire?

I normally recommend that people stay for at-least 3 months, preferably 6 months.

Is it possible for employer to initiate GC even when I have Change of status to H4 EAD & staying within country?

Yes, this is possible. Work closely with the company's immigration lawyer.

It is never good for anyone to work on a 1099 .... it is usually used by companies as a 'tax dodge'. Is it legal? Yes Is it wise? No