Yes, we will be able to live in our own house and not throw away our money in rent, but we will lose all the cash flow because we will need it to cover the primary residence mortgage. 

If they don't pay or violate the lease in any way, they can lose their vouchers. 

This is why you need to do a ton of due diligence on them and make sure they have skin and the game and something to lose.

The risk is too high of losing everything.

It depends on if you want to make money or lose it. 

As your equity grows, your cost grows to a point where you are losing money with its growth. 

Either1) your startup takes off and you can distribute profit fast enough to pay off your debts, or2) you find another source of $100,000 a year (which barely even starts to pay down the $300k, but might provide a better chance for a better loan), or3) you BK and possibly lose the rental houses to creditors (hopefully not, but we don’t know how they are held), or 4) you sell the houses, take the tax hit, work with the IRS on a payment plan whose interest will be much lower than your CCs, and focus on the startup.  

If you listen to David Greene, he's hearing more and more stories about syndications struggling to keep up with their promises and a lot of investors are losing money, or pouring more money into the syndication to try and save their original money.

You'll probably lose a little, but at least you'll be done with them and can start fresh.

Regardless of what you do the senior will likely lose their low rent situation whether you buy the property or not.