Check the regulations of the area since Memphis has some areas you'll need to avoid.

Have you had any issues with the city regulations regarding STRs using this method? 

Regulations differ by cities, so you'd have to check for each market.

Of course there are nuances like everything regulated by the IRS but like I said it's basically not that hard to stay in compliance. 

The requirements, costs and regulation is different in every state.

I want the concept plan to illustrate hypothetical lot layouts with different zoning regulations such as R20, R30, R40, PUD, or special use.

My default position has always been, "No one will take better care of your property than you".However, here's a list of issues that can force you into using a PM:Out of State - non local propertiesRE inventory that requires too much of your personal timeSpecific properties with a unit count that then require onsite managerIn Calif, (3) the count is 16 or more units, and if you hire a manager, then you have to follow all the employer regulations, which easily adds 35% above the salary. 

But to get you started, a few inexpensive items you can implement to improve the park quickly - create good rules and regulations for the park and enforce the "No Pay, No Stay" policy; improve the road frontage with a white 3 rail fence and new sign; do not allow dangerous breed dogs.After that, find the money for MHU Boot Camp and attend :)

If you are starting out with rental houses, get ready for more impossible rules and regulations and higher costs for repairs. 

There are conflicting regulations as to the exemption of 2 or 3 deals by a seller and these may or may not apply to dealers in the business of real estate, so check again at the state level and to assume on the safe side, go with 2, not 3.