I'm not sure I understand the question, but as long as you give the current tenant the legally required length of notice for the non-renewal of the lease, after they move out, someone else can move in immediately.Edit: if it's clean and move-in ready

We'd legally rent it back from January 2019 through May 2019 and be moving out of state turning it back into a rental.I'm not looking for "that's a bad idea" - I'll come up with those conclusions on my own .  

In most State a mailbox would not be enough as you need a person to receive service of legal documents..

Ideally, you should find one that has experience dealing with medical/dental offices since there are some practical considerations to think about on the legal end.  

So I'm new to the wholesale market, I'm slowly getting the hang of how to go about getting leads on houses for sale and generally on selling over to the companies, can anyone help explain more of the legal side (contracts with home owners/contracts with buyers)Thank you for your time

Rehab holdback of $42,500.Loan Term: 12-month interest-only balloon note.Payments: Interest-only monthly in arrears with balloon paymentat maturity.Interest Rate: 9.99% fixed interest rateCollateral: A first priority lien on Borrower’s fee simple interestin the Property and the improvements thereontogether with any personal property owned byBorrowers related to PropertyPrepayment Penalty: noneLoan Fees: The following fees shall be due: (1) 3.00 points, pluscustomary underwriting, processing, legal,administrative and site inspection fees to (**) at closingof the loan; (2) $50 application fee due upon signing ofthe term sheet.

You can do it but properly doing it tends to cost a lot on legal fees to do it properly to protect both parties.

Banks also tell me I'd be a bad investment if I were to get a non-legal job in Florida to supplement my income while growing my new firm, since I'd be working far beneath my education level. 

I’m hoping the landlord will allow us to just pay for the next month while we wait on closing and moving our equipment and inventory over, but I’m curious what they can legally do to make us vacate should they become unhappy with the situation. 

Do not rely on it for legal advice.