How can I get my roommate to move out?

It's going to be difficult for you because it seems like you violated the lease yourself. You can contact an attorney for your options.

Can a landlord/housemate deny access to the air conditioning unit while tenants are under the eviction process?

Refusing to pay rent is referred to as self-help and is generally prohibited even if you think the landlord is in the wrong.

What can I do ? Can I sue them because it's ridiculous , I was not on the lease/ she didn't get permission for me to stay there

It doesn't seem worth your time and money to pursue this in the courts.

Are there different laws for arrangements where the landlord is also a tenant?

What does the lease say about moving out early?

Can I get the permanent resident before master hearing date schedule at 2019?

It is possible, you are on the right track. Consult an attorney for more details. Many offer free consultations.

My Present Employer is not willing to provide the I-140 approval receipt to me as he doubt's that I may leave his company.

If Employer B has a lawyer then you should address these questions to him/her.

Do you know if USCIS has announced that the cap for 2016 on U visas have been reached?

if you need further assistance there are many free legal clinics that can help.

Should he/she put the staffing agency or the company he work? He gets paid from the staffing agency.

Which entity pays the person's salary and issues the W-2?

It very well could. Has the landlord cashed the $300 check?

Impact of Canada Inadmissibility on US immigration (Non Criminal)

Crimes committed abroad can affect U.S. immigration processes but it depends on the severity.