You can but it will be difficult to get one given this kind of immigration past.

Im separated from my husband for 5 years but not divorced if im applying for citizenship do i need him?

No, you are eligible to apply for citizenship on your own without his assistance.

My husband was denied a Green Card because we left the USA during processing. Can we simply refile the I485, or start from I130?

Unfortunately you did not hire an immigration attorney who could have told you that he shouldn't have left the country without AP while his...

Reinstatement and filing for a green card

If you never got an NTA and never went before immigration Court you probably were not issued voluntary departure. If you simply mean you were...

I-130,I 485 /application

What advice does his immigration lawyer have on all this since no doubt with such a difficult case he has hired one?

Will there be immigration issues if my Fiance enters the US through the Visa Waiver Program for our marriage ceremony?

No if he complies with the requirements of the VWP for instance by timely departing.

I am an international student with F-1 visa. I need to open a company in Dallas to start my business.

If you do this, you will directly be in violation of your F1 status which does not permit you to work unless specifically authorized, usually due...

I am in a F1 visa but my wife wants to join me and be able to work in the States during my studies here. How can she do that

You could bring her here on an F2 but she wouldn't be able to work lawfully in that status.

How long can I stay in US legally if I have F-1 visa and an I-20, but decide not to attend the school?

There will be a maximum grace period of 60 days.

I never renewed my EAD but now I have a green card and I'm applying for Citizenship

No it should not affect citizenship eligibility. Furthermore, as a green card holder you will not need an EAD to work.