For the "receiving cash back" I wrote a pretty lengthy article about this subject and how to properly structure a cash purchase. 

So I did a quick google of "residential occupancy limits Raleigh" and learned about Raleigh's definition of the Rooming Business.Then I also came across this article from 2014 where  Chapel Hill finds 12 tenants in house, fines landlord $60k.

If you haven't already, I would check out Scott Trench's book Set For Life and mrmoneymustache.comAlso, although not directly relevant to your situation, here is a specific article from Mr Money Mustache that has a lot of really good points. 

Rather it measures until 7.5 G are used and then 'ticks.Take a look at this article to get a better idea of how things work inside a water meter;http://www.balkanplumbing.com/how-a-water-meter-wo...Oren

I read an article that suggested that 0.8% to 1% of the principal is your rent?

Rent Control article for California and likely impacts.

I've read through all the articles and I'm happy to say they are really taking steps in the right direction.

Of course a lot depends on the condition of the park, location, whether it is POH or TOH, utilities ownership and etc.Here's an article to give you a general overview: https://www.biggerpockets.com/member-blogs/10850/88862-pros-and-cons-of-investing-in-mobile-home-parks 

Link to article:  https://www.mpamag.com/commerc...

There will also be more requirements for an FHA loan (http://www.investopedia.com/articles/mortgages-real-estate/11/fha-minimum-property-standards.asp)@Juan Gonzalez If you think you can handle a quadplex then go for it.