To be perfectly blunt (sorry I'm a very direct person), you have not earned the right to have the same problems as the other people you know. 

However, banks are paying such a minimum interest rate that that fee could be more that the interest earned.

I understand this is not sustainable with the mortgage so we are going to pay $50k on the principal to make it self-sustainable.We should be able to save approximately $50k/yr combined for the next 5 years safely.Should we pay 40k/yr additionally on the home principal to get it paid off in under 10 years to earn fixed income and sell when we want to retire/start a business?

Last year the taxes went up on one of our properties and took a big bite out of our earnings.

I don't know how much of your 100k you are carving out for investing, nor do I know what type of earnings you need on an annual basis to live off of, but with that kind of pot, I would think you'd be able to do fairly well in BRRRR or Buy/Hold in Pittsburgh.

Work is beyond stressful, I have guns pointed at my head from people trying to rob my safe, and nothing but disrespect from my patients--all to earn a high income salary and get three weeks of vacation per year.

Only to have to do it all over again if you want to earn money again?   

Can you use some/all these strategies mentioned above to save and earn more money?

Make sure her degree is something that she can actually earn a living in and pay back those loans. 

Either way,  it is super unlikely a seller is paying taxes on money they aren't earning.