It would be better to apply once your spouse becomes a USC.

Am I eligible for H1-B in April 2018 if I am on F-1 visa until August 2018?

You can apply, if you have completed your program of study and have the required degree in a specialty occupation.

I’ve a marriage based Form I-485 pending, will I be denied entry to USA if I come back from my country with ADVANCE parole ?

If you have advanced parole you should be admitted, if there are no other issues in your case.

Do I need a new H1-B stamp ?

Yes you can re-enter without applying for a new H1B

I have been marriage since March 2017 but I havent sent in the paperwork...if I sent it in now , how long will the process takes

It takes about 10 months for the USCIS to adjudicate marriage petitions.

21 year old girls needs to apply for American citizenship ... can her 18 year old sister sponsor her?

Her sister can only sponsor her for a green card if sh is a US citizen.

J1 holder who doesn’t complete the 1 year term ?

It's up to the consulate office, but you should inform them right away.

Time frame between sending documents and green card interview based on marriage?

It takes about 10 months and no you have to have the conditional card for 2 years and can apply for the permanent green card 90 days before your 2...

U Visa application /I918B

You do not have ot resubmit unless the Vermont Service center makes the request for the updated form.

Hi, May I send all forms required for the green card process in one envelope (for both parents)?

Yes you can, just label them as separate petitions.