We were contacted by our PM regarding this coverage and they recommended this company.  

So I would think that any good cleaning company could come and do a deep clean after a 3 month stay just like you would with a LTR tenant flip.There should be a ton of cleaners in that area.

I bought the building that my C corp business rents with a LLC company I own.

That gives a clear consequence to the tenant, and also gives the property owner a clear reason to evict (if necessary).If you're unsure about the legalities or the best approach, consulting with a property management company familiar with local laws or a real estate attorney could be invaluable.

Then, you’ll pay the agent (say 3% for the sake of argument, $5,400, since they’ll be doing a lot of work for you on this - I’d order that prelim/TRIO with my escrow company, and help you find lien records if any, plus provide all the contractual guidance to make sure you don’t lose your earnest money).

you should get a RMLO or an underwriter to qualify the borrower. if its owner occupied and in florida you also will need to use a third party servicing company to service the loan which will run you around $450/yr. not an accountant but its my understnding unfortunately the interest income is going to be taxed at ordinary income and the principal will reduce the principal. how you offset the losses talk to your CPA.your best bet honestly is to just sell it and bite the bullet. 

The 3rd party property management company wants this onsite manager to be the employee of my LLC, which I am not sure with.

We are in the process of building a property management company, does anybody have a simple Property Management Agreement you can share with me? 

The LLC formation combined with operatring the company in accoordinace with the operating agrement & appropriate funding to present itself as a viable business is what's needed.

I'll reach out to my company, as well as several other lenders I've worked with and see if I can find something!