I know he will be able to give you the proper guidance that you need in order to make a sound decision.

Take ownership of your mistake and learn to do the proper due diligence recommended above😊

Trying to balance proper due diligence against my desire to just acquire a bunch of mediocre units!  

Structuring the agreement properly, outlining how profits will be split, who covers the rehab costs, and what the timeline looks like can ensure the seller feels confident in the process.

Are they properly licensed?

This strategy balances tax efficiency with proper estate planning.

The guru your son is learning this technique from is likely not telling your son that the deal will almost certainly encourage your son to get an "off-market" deal from a "wholesaler" who is unlikely to properly disclose the details of the property or encourage an inspection. 

Yes it does, needing to keep the books and properties seperate for proper Tax Reporting and any 1099s you may need to file can be costly.

that we’ve learned in our 24 years, managing almost 700 doors across the Metro Detroit area, including almost 100 S8 leases:Class A Properties:Cashflow vs Appreciation: Typically, 3-5 years for positive cashflow, but you get highest relative rent & value appreciation.Vacancy Est: Historically 10%, 5% the more recent norm.Tenant Pool: Majority will have FICO scores of 680+ (roughly 5% probability of default), zero evictions in last 7 years.Class B Properties:Cashflow vs Appreciation: Typically, decent amount of relative rent & value appreciation.Vacancy Est: Historically 10%, 5% should be applied only if proper research done to support.Tenant Pool: Majority will have FICO scores of 620-680 (around 10% probability of default), some blemishes, but should have no evictions in last 5 yearsClass C Properties:Cashflow vs Appreciation: Typically, high cashflow and at the lower end of relative rent & value appreciation.

If they're delinquent after only 2 months, they're either facing sudden life changes or you did not properly screen them to begin with.