Drop the rent low enough to accommodate for this problem until its resolved.

I would have collections tie this to their credit report until resolved. 

You might want to check Florida Landlord - Tenant Law, but I believe that if the tenant wants to withhold rent, they still need to pay rent into an escrow account that you can have access to as soon as the situation has been resolved.

If you did not contact your LL and try to resolve it the problem is not him.  

After the building was fixed up and any issues in their units were resolved they magically started being good tenants!

If there is humidity, poor ventilation/lighting and no emergency egress (via door or large window), then forget turning this into livable space and focus on storage, although the humidity needs to be resolved (sump pump and/or dehumidifier).

So if I were to say jump to a 5-plex or more right away that would resolve my concerns and issues with funding acquisition because I would then be in the commercial realm of lending and does that mean an LLC would be the route to take? 

Hey Eric, did you ever get a resolve to this?

They are not compatable.

HOWEVER, if I have something needing attention, I walk right into my broker's office and have a face to face with him to resolve whatever is needing attention.