A separate private entrance could be easily added with a deadbolted door to the main house.

But if I sold it all together, house with contents and contents not separately valued, I'm guessing none of it would be taxable (within reason of course/assuming absence of fraud).A similar scenario that might occur is when a house burns down.

That tells you a lot.I would be looking at all this stuff way BEFORE you hire an inspector......Typically inspectors only check the water pressure coming into the house, but not the pressure of the pipes.On a house that old, I would also hire a separate plumber to scope the sewer pipes, unless you know PVC has recently been installed....probably $150.You should also have termite/WDI inspection as part of your home inspection.

If this works we would probably do more properties in Oklahoma, and having a proof of concept would help separate our Friends/Coworkers/Family from their cash to invest with us.

But if I sold it all together, house with contents and contents not separately valued, I'm guessing none of it would be taxable (within reason of course/assuming absence of fraud).A similar scenario that might occur is when a house burns down.

How would we go to find a duplex or a home with a separate unit as a way to house hack.

The key to this is maintaining the "corporate veil", which implies that the LLC operates COMPLETELY separate from any other LLC's or individuals.

If you can use it as office space, maybe you can lease it together together with one of the units.Or can one of the other units be rented as a unit with a addition separate entrance in-law suit and set it up so that those 2 units are linked through the lease as one unit even if they are not physically connected?

My wife and I have been filing our taxes as Married Filing Separately due to my wife's hefty student loans.  

I did 1 closing, I have 1 insurance policy for the prop, I did pay taxes on 4 units separately but i also do that with a duplex that I own.