Fastest way: BRRRRBut the ideal strategy is based on your time commitment and current expertise. 

The other 3 cities would likely be much more ideal.

I deal with lots of people on a daily basis with my 9-5 job and love it, however I wanted to take the time to show lots of people so I could get a feel of the clients I was working with in this area. 

Unfortunately not enough equity in my primary residence currently and I do not want to take from my 401k; ideally I am looking for a partner.

The ideal way to calculate capital expenses is make a chart of all items in the property that can wear out.

I deal with low income housing.

HOAs are required to keep x amount in reserves for capex (as dictated by an annual reserve study) so that you [ideally] don't run into the need for special assessments. 

These are small ducted units ideal for top floor bedrooms or 1st floor rooms where you can put the unit above the ceiling and run just 2 or 3 small ducts to the area being conditioned.

Even a 4 bed is likely to attract families with more children. 3 bed are the most ideal as rentals. 

Ideally you can always be selling the house you rehabbed in a prior year and renting the one you just finished.