Spend a significant amount of time on every line of item of income and expenses, especially repairs & maintenance, management, R&M/payroll  (the time - or payroll expense - needed to maintain, manage) and cap exp items, like replacement items that may possibly be needed such as new HVAC units, roof redone, etc...  

Its high level info from very sophisticated investors. its called cash flow connections. 

Do you have a “payroll”?

As to protecting that valued relationship with your friend, know that technologies used in downloadable forms just are not sophisticated enough (yet) to get you to think through the kinds of critical  "what-if" scenarios that typically don't get asked without the prodding of an attorney.  

The one who writes the check (upon completion / verification) immediately or the one who you submit a bill to and they put it in their "payroll system" that takes 3 weeks to issue a check? 

Bonus tip: If paying out of an LLC that is disregarded, which yours is as you stated it is a single member LLC, then you and your son don't need to pay FICA (payroll taxes).

Here some of the top 3 take aways from investing in this asset class.Pros Yearly lease escalations is really nice.The tenant base is more sophisticated.Persistence in a good trait to have.Having a good team makes a big difference.Cons It costs money to bring in new tenantsThe competition has lots of capital, but nothing beats knowing your turf very wellAlways read the details of leases (the tenant base is quite sophisticated)

I imagine many non-profit leaders don't have the training and sophistication to put their money toward syndication deals, so they go with the first financial advisor they know.

Excel tends to be considered less sophisticated than other software platforms but it can actually be extremely powerful and you can customize and program it to fit your exact needs. 

Ask if they ever lost money and how they handled it.Ask for contact information of current and past investors and talk to them about their experience but also pay attention to their level of sophistication.