First thing you need to do is separate the two entities- the house and the park.The house- Get the appraised value of the home which should be easy enough to do. 

We used private money and seller finance for acquisition, raised rents, renovated one building, and sold each building separately as 4 unit buildings.

The sections of pipe are separated, so I'm thinking it's an open trench job. 

I would keep your businesses separate.

SMLLC is disregarded and does not have a separate filing requirement (gets reported straight on the Form 1040).I can't speak to the implications of a potential divorce, I would consult an attorney. 

We did set up a separate LLC and purchased and manage our properties finances through it.  

I further believe (though would not underwrite to this) that this approach would offer the buyer the potential opportunity at a future date to conceivably subdivide the parcel and sell the main unit and ADU as separate properties.

I am thinking that perhaps we could insure building and operations separately and that might open some options in insurance providers.

I am now looking for advice on how to structure my bank accounts to properly separate my personal expenses from any expenses surrounding my house hack.

Keep the agents list and the investor lists separate and you should have another good out for your deals.I've also worked with builders in the past, sometimes some of the smaller builders will flip houses as well if they can slot and ADU somewhere on the lot.Best of luck!