We've had this kind of problem before, and honestly, it seems to just gradually get worse and worse until we can get the tenant out.You can schedule frequent inspections to get inside the house and check the condition and count beds and toothbrushes.You can give your business card to all the neighbors and see if any of them are willing to have a camera to record the house set up temporarily.You can hang back and wait for it to play out.You can stop by the police department and see what they are willing to share and if they have a program where you can copies of all calls to the property.You can send a cease and desist letter stating that if you get any proof of criminal activity or extra occupants there will be no leniency.  

Does anyone have suggestions of a broker that allowed them to hang their license for a nominal fee?

In my opinion, you'll want to get the hang of managing one and then find ways to manage more.  

Now, Lowes stores seem understaffed with employees trying to hang out "in the back" and away from customers, if they can help it.  

As a reminder, he has the legal entity set up so my girlfriend can 'hang' her license up there and will be its corporate broker.

Try and get the hang of things.

Don't plan on doing anything buy my own stuff so am not looking for a big name outfit, just a reasonably priced place to hang my shingle. 

Get your real estate license for Florida, find a brokerage that will let you hang your license and not charge you ridiculous desk fees or anything like that.

Get your RE license and hang it under a broker who is willing and able to show you the ropes.

One of my biggest hang-ups from getting started is the contracts.