I would tend to agree with the other CPAs typically.The 500-hour test is one of seven material participation tests used by the IRS to determine if a taxpayer is actively involved in a trade, business, or rental activity. 

Quote from @Garry Lawrence: I need advice on a serious situation involving a property I’m about to buy.

This allows you to test all the systems and the people involved.  

The deal will involve complicated paperwork. 

It’s doable, just more difficult, time consuming, with a lot more “contacts” needed for each “sale”. 

I just want to be involved and learn more so I could achieve more eventually.

The client can distribute proceeds through a private agreement without involving the title.

I think if you are going to keep all three parties involved as owners of the deal long term then you need to separate yourself as a renter and a contractor.

Pricing models vary, but I use a flat-fee approach based on the intensity of design strategy and level of investor involvement.

Understand the fees involved and calculate the total cost for an entire year of management so you can compare the different managers.