Clear boundaries and expectations and the right legal documentation would be very important here.Partnerships already complicate business, it would be even more complex having a partner as a tenant.With that said, you might consider a 30/50/50 split or a variation thereof.

Also, annual taxes usually increase.Here's our standard post about Michigan Property Taxes:Michigan has some of the most complicated property taxes in the US.First, Michigan uses the State Equalized Value (SEV) to determine INITIAL Taxable Value.

Do I need to develop a mobile home park like it's a commercial property, which seems to be too complicated? 

Don't complicate it too much. 

These passives losses are carried forwarded.You can rent out your primary residence, but that does make your taxes more complicated since it will be both a residence and a rental. 

It should not be that complicated, really.  

Your deal is more complicated because its across state lines.

And to add more complications to this, a bank may not want to qualify these properties on STR income.

The first surgery a surgeon performs generally isn't a complicated one. 

It needn't be complicated and full of legal jargon, but it should clearly spell out responsibilities.