It is not clear to me if owning a property and leasing it to others constitutes "doing business"  - in some cases it does not.  

ABC Holdings LLC, and each MF property will be its own series (unsure if I will do a registered or protected series yet).Is there any problem creating the Operating LLC as a series within ABC Holdings LLC?

we own a home in a rural community and the home runs on propane, all utilities including propane are to be covered by the tenants.

Make up your own terms. 

We’ve done it with another property we own in CA where we managed it ourselves and eventually it cash flowed.

You will need 20-25% down and a commercial loan for the rest.Most lenders will want to lend to an LLC with you personally guaranteeing the loan.Typically, each MFR would be purchased under its own LLC, for liability purposes.Each LLC would then also need its own bank accounts for collecting rents and paying expenses.

They usually know their own limit.  

I would love to be able to hand wash my own car at a self-service car wash.I did find these resources for you to check out regarding repurposing car wash bays:Alternative Uses for SS Car Wash Building | Car Wash ForumA creative adaptive reuse for a former eastside car wash | Anderson Management Company (amcwichita.com)9 Ideas to Transform an Old Car Wash Bay (superiorcarwashsupply.com)I hope these are helpful!

You as consumer have no idea who owns that company.

In general, it is always good to look at the taxable value every year for your property while you still own it when the tax statement comes.If you feel you can support a lower taxable value with sold comparables that are like your property nearby, then it is worth your time to try to dispute the value.It is true there is a very short timeframe to schedule a time to go in and dispute the taxable value with your local property tax assessor usually and the deadline is printed on the annual tax statement.The reality is real estate does not always go up in value.To your success!