Write USCIS a letter. Reference the receipt number and ask to withdraw.

I797C instead of I797A

You probably were out of status this is why the C form was given instead of A.

Can unused H1B petition be used if revoked by 1st employer??

Yes if it was approved and counted towards the quota, yes.

Application for Citizenship N 400

You do not need to report this on yoru N400 form.

Is it possible for an undocumented immigrant to fly within California, with only their foreign valid passport ?

Yes. Usually, with some exceptions of course, all you need as a valid passport.

Applying for a work permit for an undocumented immigrant through a lawyer

What was the reason for the EAD applicaiton? DACA?

Does my asylum affect my sister when she will do an interview in the US embassy?

Probably. She will have to disclose the fact that you are here and seeking asylum.

On L1A Visa Sponsor company is closing down

Depends on the visa. H1B would be a good choice but it is not available for CAP subject applicaitons until next April.

F1 Visa/OPT/Green card query

The fact that your EAD was denied should not have any effect on an adjustment of status petition filed by you together with your USC spouse...

Hi, I have valid F1 student visa with Duration of Status (D/S,) studying an English course in college.

You need a valid F 1 visa stamp in your pasport to return to the USA.