While sending civil and financial documents, and I-864, am I supposed to pay another filing fee?

NVC should have sent you detailed instructions. Please review, reread and follow those instructions.

At a minimum consult with an attorney to assess if you need to retain one. You can do a search on avvo. You should also gather all the certified...

Do my employer need to file H1B Amendment for my case or not?

Talk to the employers immigration attorney. I think this is a duplicate post.

Can i file the application without the taxpayer or sponsor? if not what should i do?

You will likely need a joint sponsor. Talk to an immigration attorney who can review your options under I864. (and talk to you about AOS).

Will I get a chance to have a legal status again?

Please contact an experienced immigration attorney. You can do a search on avvo.

I have I 140 approved, worked 8 months on H1 b so far, worked on same H1 b for 1.6 years before. can I change employer with h1b

Please talk to the company's US immigration attorney.

How can I sponsor my Fiancee for GreenCard after she comes here on H1B?

Once you are married, you can file a I130 and then when the visa is available she would be eligible to adjust status. I would talk to an...

You should replace (renew) the GC and you can do this via the I90. Prior to that talk to an immigration attorney to see if naturalization is a...

Maintain F1 status

I would have an attorney review your AOS documents. If married to a USC, it should not necessarily pose an issue.

Do I need to file Amendment?

Talk to the company's immigration attorneys please.