On the income side there are numerous things you could do to improve revenue but they are not listed.  

I personally use RevMax software with a live revenue manager. 

Consider short-term rentals: If local regulations allow it, converting one or more units into short-term rentals via platforms like Airbnb can increase your revenue per unit.

Even if it's the biggest unit, you need to move into that one to satisfy the mortgage if it's liveable and then figure out how to get the tenants out.Who was your agent on this because they have not prepared you for anything? 

And seeing as it's an organization level with so much staffing we need HR, middle managers and organization managers.So now we are at a place that the staffing "suck" eat's up the revenue of a couple K doors, so we need more doors to make up for that, AND as we add doors we add more staffing requirements, which add's more "$-suck" so need more doors to get over that and it's a lovely feedback loop....... 

The biggest thing I'm seeing actually isn't his residency status, but I think you'll have the biggest issue with the value of the properties you are looking at.

One of my biggest questions is could I sell that second house on its own once it's built?

The term "investor friendly" is the biggest joke!

So, I believe some of the fundamentals of larger multifamily (increasing NOI via increasing revenues or decreasing expenses) are beneficial to smaller multifamily although the ultimate value is not determine by NOI, but by comps. 

Imputed value comes from taking the assessed value from the tax assessor and multiplying by the applicable factor that the PA Dept of Revenue has determined for that county and year.