I do not plan to live in any of my units - I have a family, dog, house that makes that option very undesirable to me.

but spending 25 bucks on a permit is tiny compared to the fines they charge you if you are caught.You will need some sort of stud, either wood or steel (check with local codes), 1/2 inch dry wall, sheetrock tape, bucket of mud, 1 inch,  and some bi fold doors.  

This one has a MUD at the southern border of the property I am trying to see if will allow a water / sewer tap sometime in the future or for redundancy / emergency purposes.In Texas and many other states you can pass along the submetered (or allocated) costs of private utilities to cover the cost of the service - the risk is really about the capital costs (hence diligence), and less about run & maintain if you're doing that properly.My point to all this nonsense is that you're already taking on additional risk by evaluating a smaller park, you might as well keep private utilities on the table if they're in good shape, you can get comfortable with them, and use it as a negotiation point for instant equity / further upside.But I can see from your story @Paul Stout that the existing septic there looked like a big problem, and for a small Park could make the entire economics go sideways.

I’ve been looking into getting some rentals but the more I look into them the more I feel I’ll get myself into dealing with undesirable things.

Taking shortcuts or leaving it to others to "figure it out" usually leads to undesirable results.

$4800 for a 1000 SF house, walls. ceilings, mudded and textured, is not bad.

You might find available services don't meet your needs, or have undesirable terms.

We have our fair share of undesirables, but you can usually weed them out with proper screening!

Mud season is the hardest, March and April.

I also think there may be some value in creative solutions for undesirable lots / houses that are not maximimizing their zoning potential / building higher end properties / or getting a head start in an under appreciated neighborhood.