If my fiance has never entered the U.S will I still qualify for the fiance visa?

Yes as long as you have met personally within the last two years and he does not have any grounds of inadmissibility.

Sent copy of I864 and I864A instead of original?

No your case should not be denied for this and if needed USCIS will request an original. You should bring the original with you at time of interview.

Will it affect my bf if he marrying me while applying for citizenship ?

No this should not impact his application and he should disclose all information truthfully.

As long as your marriage is in good faith and not for the purpose of evading immigration law and there are not other grounds of inadmissibility,...

Can i travel with a pending I-751 and no biometrics appointment scheduled?

You should schedule an jnfopass appointment to confirm that USCIS has received the transfer request.

My student visa got denied twice in my home country. Can someone help me with this?

You will have to attend an interview and an attorney cannot prevent this from happening. A review of the previous denials must be done in order to...

How to answer Q 17 if I answered yes to Q16 in Part 8 of form I485?

You can answer each question separately with different answers depending on your personal circumstances. For guidance consult with an attorney.

My friend has California bench warrant. Will he be able to get B1/B2 visa to enter the country?

The renewal may be an issue given the pending criminal charges.

Can I send an invitation to my sister in law to come to the states with a b-2 visa?

Yes you may do so and submit an I134 for financial support purposes. Consult with an attorney for guidance.

I want to write a letter for an asylum because of my sexual orientation?

This is something that requires assistance from an attorney, especially for the actual filing of the application.