I focus on residential but have a background in commercial so am very familiar with both.

As some background, I just had a MassSave home energy audit and 1 of the hot water heaters and the gas space heater came back with above code readings of CO emissions, so I need to replace those before I can proceed with the MassSave insulation work. 

A little background, We have been in the game for 10 Years full time,  experimented with many different rehab models, we rehabbed 15 houses last year and wholesaled (bought and sold) 28  houses to a couple other rehabbers, half of them to former employees who are now doing their own rehabs. 

Background check not ran.

I also use them for background checks.

It's always great to see more folks with a strong REI background Since you've got a background in real estate, you might consider linking up with some of the newbies in your area to share your experiences!

I'm sure there are tax and legal implications with ownership, her level of participation, etc. that need to be considered that I am not sure of based on the scenario/situation/result that I want.Of course, I should consult a tax and legal professional for my specific situation, but I wonder if anyone here on this forum can directionally give me some guidance on any possibility in my situation here, so then I have a foundation and basic background to pursue.  

My thoughts are if he is going to partially live their, even once a month, then he probably needs to be on the lease agreement and also go through a background check.

When I buy places, I fix them up nice, and I rent only to people with a clean background, good income and stable household (as much as I can ascertain).

Since you've got a background in real estate, you might consider linking up with some of the newbies in your area to share your experiences!