Do I have legal obligation to pay rent with 20 days notice given of moving out (NYC-Brooklyn)

No, in New York City, you are not obliged to give notice of moving out.

Is there any legal action i can take towards a tenant who smokes marijuana/tobacco?

Legally, you can move against the marijuana, but not against the tobacco. Realistically, neither. Tobacco is still legal in one's private home...

Is it legal or discriminatory to decline a lease renewal based solely on the fact that a social security number is too recent?

Tell them that you intend to file a complaint with the Division of Human Rights. See where that gets you. If telling them gets you nowhere, file...

I have 3 tenants (a girl and a couple) living in one of my apartments. The couple told me via text that they would be moving.

If the apartment is vacant, you can offset the security deposit against the rent that is owed. If the apartment is not vacant, you should be suing...

How is responsible for high water bill due you leak?

Try to work it out with the landlord. You should not have to pay both for the toilet and the leak and it really doesn't pay to have this battle for...

If I get fired from work, can my landlord throw me out during winter??

Evictions are year round events. However, they take a while to proceed. If you are not behind on rent yet, the chances are that you won't be...

What are my options for a landlord refusing to refund security deposit?

Sue in Small Claims Court or file a complaint with the New York State Attorney General.

Will I be involved in the illegal house rental?

It would be very rare that the Association would restrict rentals, but not unheard of. If you want to stay in the house, you need to have a lawyer...

Call Code Enforcement. It won't help you with your rent, but you are still entitled to a healthy apartment.

I was subleasing a room in an apartment. Do I have rights when it comes to getting the Security deposit back?

You should sue him in small claims court.