Can owner choose contractors?

The owners of the company have 10 acres where they build a few manufactured homes and use those as STRs.

https://www.irs.gov/newsroom/how-small-business-owners-can-d...

If I wanted to owner-occupy a 5-10 unit apartment building, would I be able to do 5% down conventional financing or must I do the 20% down simply because anything 5+ units is commercial? 

They have so many great resources for owners and the community of hosts, property managers, and other vendors. 

App_mode=Displ...197.172    Interest rate; calculation and minimum.(1) Real property taxes shall bear interest at the rate of 18 percent per year from the date of delinquency until a certificate is sold [...]Translation: Property owners who are delinquent on their taxes, for which a tax certificate (i.e., tax lien) is sold at auction, are charged 18% per annum.197.432    Sale of tax certificates for unpaid taxes.(6) Each certificate shall be awarded to the person who will pay the taxes, interest, costs, and charges and will demand the lowest rate of interest, not in excess of the maximum rate of interest allowed by this chapter. [...]Translation: Florida is a bid-down interest rate state. 

The owner of that property did not have insurance because the they believed it was a waste of money if the house was paid off. 

For example in many jurisdictions I can STR units in a duplex but cannot STR an ADU (some jurisdictions will let you STR if you owner occupy).

Even if the change in ownership is merely a formality and effectively I'm still the only owner? 

Once I get in contact with property owners, I have no way in Propwire to actually make notes on what was discussed, callback time, etc.