Make sure you talk to a Banker or Loan officer that is well versed in both SE (Self Employed) income and also Non/QM programs.One tip I will give you as a Banker is open up a "Business Checking account" and for the next 12 months pay "Everything" out of that account. 

In Philadelphia the fundamentals are strong: leading industries/employers are in the Education and Medical fields which are known to be stable, proximity to NYC and DC, national airport, port city, affordability compared to mid-atlantic predecessors.

If you'd ask this question while still employed I'd say apply the $8500 toward knocking down the debt quicker but since that is not the case I would build up your reserves to about 6 months then begin applying those funds to bring down the debt. 

Do you provide personalized guidance, or is the mentorship more of a one-size-fits-all approach?

Time and practice will still teach you as you do deals but it will help you understand what things costs for the size of the property 

If you building 2 , again depending on your lot size and projected finishes. 

If you go back to work as self employed, there are some NonQM programs out there that can do a cash out refi after just 1 year of bank statements or P&L. 

When choosing a location for your first rental, it’s great that you’re considering factors like crime rate, population growth, employment rate, and price-to-rent ratio—those are all key metrics.

The big pros are the strong job market (lots of major employers), good population growth, and still-reasonable entry prices.

Same thing for the size of the Heloc but you'll get better terms on the Conventional vs Heloc.