How could I get married?

Contact the person's consulate about applying for a replacement passport for USCIS processing. Contact a US immigration attorney for assistance.

Am i qualified for H1B visa?

Nationality is not the issue. Your US employer's US immigration attorney will determine your H1B eligibility based on your educational background...

Is the SSN that I had during my tenure on L1 still valid now that my visa type has changed and I am on L2?

The SSN never changes and stays with you a life-time.

Frequent absence?

You do not appear to have frequent absence issues.

Can I file for a NIW before the J1 waiver gets approved? will it affect success of NIW?

Yes. You cannot apply for adjustment until the waiver (whichever one) is approved.

Would I be financially responsible for the tourist's all visits to the America, whom I financially sponsored for one time only?

No. You will not be financially liable for your family member unless you were required to complete an I134 or I864.

How to write explanation letter why visa to usa daniel

You must mark yes and explain why. Failure to provide truthful information will lead to a denial and potential fraud designation.

Will my green card get renewed if i was granted cancellation of removal under section 240A(a)? No criminal activity since then.

Follow the instructions at www.uscis.gov or contact a US immigration attorney for form completion assistance. The green card should be renewed.

You may not travel internationally while in removal proceedings or you will self-deport, whether or not you have an I131. Contact a US immigration...

Review the instructions or contact a US immigration attorney - the forum is not meant to provide specific form completion information.