http://www.hud.gov/local/fl/renting/tenantrights.cfm

Google is ur friend!!

best of luck!

If you rlandlord won't be upset about a not-on-the-lease person having lived in your home, he/she might be able to give you some info. (When I rented in NYC, my landlord wanted only one name on the lease; he didn't care if you had a roommate, but he did not want to be in an agreement with a group; only w/ one person. All roommates were considered to be subtenants of the person who had the lease)

If he's becoming violent, call the cops. Have a restraining order put on him. Change the locks.

I think your best bet is to threaten to call the cops on him. Scare him a little. If he's not on the lease it's like he's a guest that has extended is his stay. He really has no lawful right to stay there. I know it's daunting to actually go and get police involved, and could make things sour (even more than they could be), but if it bothers you enough it would get results.

Maybe you could convince him to find someone else to move into with. If he's throwing parties, he has to have friends. Butter him up, make it sound like a really good idea.

Florida Residential Landlord and Tenant Act
which is found in Chapter 83, Part II, of the Florida Statutes...use Google.

Of course, "if he won't listen to reason, there's always Towanda" -- Fried Green Tomatoes