If the rental real estate activity has an average period of customer use of 7 days or less, or an average period of customer use of 30 days or less with substantial hotel like services provided, it is not a rental real estate activity under IRC Sec 469 and one can bypass the per se presumption and apply any of the material participation tests you previously cited for a passive/nonpassive determination.

It seems like a lot of the college housing are fairly expensive due to the rent specs on the properties.

There is not really any assessment of the quality of work or customer service, nor is there a reason to use them based on fair and reasonable pricing.

Save the custom build until you're older and have lived in a few places.Look for a MFR (I think 3- or 4-unit properties are way better than duplexes), live there a few years, and then turn it into a pure investment property.

Well you need a source of deals, and a sheriff’s auction could work, I’ve seen a number of my customers be successful at that in NC.

And that may be a big assumption depending on the type of work the S Corp does and where your customers/clients are located. 

2013 properties were affordable and I was fresh out of college, working first job.

My parents let me stay with them after college so I could get a down payment for my first house, so I decided that I would use that money to make my first house a duplex to 1. cut down my mortgage payment and 2. start building a portfolio of rental properties to compliment my other retirement accounts.

They were coming into town this month for an event at the local college, and that college unfortunately closed for the rest of the semester.

We did this a couple years ago here in Texas with a local mortgage broker - she told us we could count the expected rent from the old house toward the DTI without having a lease signed (maybe because we are in a college town and it's easy to get tenants?).