Knowing the history of the physical property and the rental history is essential in purchasing a property.  

For you to be a successful investor you essentially need two things: A knowledgeable loan professional that has underwriting experience, and an excellent accountant.Later on down the line add attorney that is superior in real estate law. 

I want to make sure that in the event of a divorce, we won't be required to liquidate assets to pay out her shares, essentially trashing our rental properties. 

Ok to pay a little more without hassle of 1000 sheets of paperwork, 3-4 months of time and bank..After some time, you can refinance or not...

Yes, that is around the prime residential rate around now, but I know of no private money that would go in at this rate (which is essentially the parallel for your structure).

They put up all the money to purchase, they put up all the money for repairs, and if you find some massive issue or you just decide you don't want to do it, you can walk away and they're left holding the bag.You will find some "lenders" who say they will do this, and go through some paperwork and then at the end you discover they want "payment insurance" or a ridiculous "application fee" of a couple thousand dollars.

It's not that it can't be done --- just more paperwork.  

Once you use that cash out refi you are essentially taking a loan out on the house and now your monthly rental income will take a hit.

If so, the current lease expiration date is irrelevant, because SEC 8 will require a new owner to create a new 12 month lease and recreate the paperwork to enter a new contract with HUD.  

What paperwork is involved in changing things over?