You don't have standing to enforce the lease. So don't even think about that. Yes, you can sue in State Supreme Court with regard to the nuisance...

Is the landlord allowed to bring a friend in my home to fix the hot water and furnace and then take pictures in every room?

Once the landlord is there, he can do what he does, but you can insist on his leaving. The pictures are admissible since this is not a criminal...

The charges are probably properly deducted from the rent, although you would be entitled to a statement of when these charges were incurred. As to...

Is the overpayment we made legal as to them having to give it back as soon As we picked up the error?

You are entitled to the rent credit. If the landlord refuses to give you the credit, you can sue for it in small claims. However, withholding your...

I would like to evict my brother from my household

Your brother is probably there as a "licensee." There is a special proceeding to remove licensees after serving them with a ten day notice....

Can someone who used to live in a unit and got removed off the lease get back the security deposit?

The landlord is right to pay the security deposit back to the one who paid it. However, are you moving out?

What if a 30 day notice arrives after 30 days?

In New York City, the tenant does not have to give notice to the landlord. You do not have to worry about the delivery date of your notice.

Can I go get my stuff out of the apartment and how soon ?

Contact your landlord to get access to remove your things. The landlord doesn't get to keep them. Do this right away.

If your sister had a lease, nothing changes with the change in ownership except to whom she should be paying the rent.

You definitely need to retain an attorney on this. It can be done, of course, but it's highly technical, although in the hands of a competent...