Standard agencies will not approve loans for self-employed borrowers who don't have tax returns showing sufficient income.

You can structure their investment as debt or as equity, ie a loan to the company (debt) or ownership in the company (equity).  

So his experience, net worth, etc were the main reason we were able to get approved for bank financing.

A nice tip is to go into Google alerts and type in words such as "{city/town} approves".

If you look here on BP, there is a lot of info on how to screen tenants.I also include as my final step in the approval process a home visit at their current residence to verify that they've taken "reasonable and normal care" of it. 

Helped him apply for and approved for rent assistance, and I got rent for 14 months a month ago.

And we have some refinancing with other property coming up that we don’t want to make a major financial change, like moving and job change, that might interfere with getting approved.

The rate is higher, but they underwrite their loans based on debt service coverage.(1.0 or greater) So you need the down payment, and closing cost money, but they do not depend on your income to approve your application.

You have set yourself up nicely by doing it on a home you will use as your personal residence and staying well under your max loan approval amount. 

In episode 85 of Straight Up Chicago Investor podcasts, @Mark Ainley talks about how in the last few years you are required to not pull credit/background check until the initial screening is approved.