Honestly, big banks have terrible rates on mortgage.Work with a broker, they are your best bet; pricing beats big banks 9 times out of 10.

With no income from the properties due to all the tenant issues, the bank foreclosed on them.

These are homes that have been foreclosed on and are now owned by the bank.

The tenants have no control over how long the actual processing takes between the banks.

Freedom from the Traditional Banking System where the only one making money in the deal is the bank. 

95% of part-timers fail because of the same reason.

I'd also suggest building a relationship with a small local bank who might consider a business line of credit for you.

This means the 50% rule fails now (50% + 60% = 110% --- 10% more in costs than rent), and other cost estimate methodologies seem to yield negative net cash flow.Am I thinking about this correctly?

Ask for last 12 months of bank statements to track rent payments were paid on time.FYI: how "deep" is their credit report?

Although rents increased by 2% annually, the purchasing power of this income is equivalent to $4,325 in today's dollars.Year 10: $5,000 x (1 + 2%)^10 / (1 + 5%)^10 ≈ $3,742Year 15: $5,000 x (1 + 2%)^15 / (1 + 5%)^15 ≈ $3,237Year 20: $5,000 x (1 + 2%)^20 / (1 + 5%)^20 ≈ $2,800Due to rent increases failing to keep pace with inflation, you won't be able to maintain your standard of living.