I've always figured it was a given that renters are harder on a house than owners and you furnish rentals with builder-grade items designed for durability, am I wrong? 

@Grayson GistThere are a couple of reasons:Occupancy fraud is the number one type of fraud in the mortgage industryMost people buy a 4 unit and then move up to a single family; they don't continue to buy 4 unit propertiesFHA expressly says in its guidelines that "FHA will not insure a mortgage if it is determined that the transaction was designed to use FHA mortgage insurance as a vehicle for obtaining investment properties, even if the property to be insured will be the only one owned using FHA mortgage insurance." https://www.hud.gov/sites/documents/4155-1_4_SECB.PDF ... so if you're trying to use FHA, you could be running into that guidelineOver 2 units, FHA requires the property to pass a self sufficiency test as well, meaning 75% of the market rents must cover the mortgage amount and they also have to apply a market vacancy rate to the mix.Lots of reasons to just live where you're living now and get a portfolio loan that has none of the above guidelines.Stephanie

The park was designed and approved by the county to have 126 pads once a new road was added.

I don’t have the money to hire an expensive web designer at the moment.

A HELOC is designed to be repaid within 5 years.   

Of course the other 40% know 50 times as much as I do.I've ended up designing software (for personal use) with it for too many things to mention here, but two of the biggest are Market Analysis and design/executing a REI Business Plan.Your skills with Excel should not be taken lightly, and can be a very valuable asset as a partner to many REI.

@Aaron T.Since Roth IRA can't be converted into Solo 401k your only options are:Self-directed custodial IRAIRA owned LLC (aka Checkbook IRA)Also keep in mind that retirement accounts are designed to be invested passively, if you do so all incomes/gains would be sheltered from taxes (in your case tax-free).

I am in the process of helping out a potential investor in the design and construction of a few multi-family residential projects in Kansas City.

Whether that matters to you or not is another issue.An S Corp is designed to minimize SE taxes based on "reasonable compensation", which will vary for each and every taxpayer. 

My husband and I brought in the contractor team, managed the project, made design decisions, sourced materials, created brand partnerships, etc...