Now, I don't know how to arrange the terms of the agreement, especially his compensation.

It does not specifically say no co-living arrangements. 

I kind of did my first deal the same way about seven years ago and my first day there introducing myself as a landlord first floor tenant told me that the arrangement with the previous landlord that they would pay rent on the first and the 15th, and then the guard told me that they had another arrangement with the previous landlord that they would do maintenance on the building and not pay more than $400 in rent.

A membership agreement does NOT magically override local occupancy laws.Cities don’t care what you call the arrangement, lease, membership, license, “dues,” etc.

-What creative strategies, syndicates, or JV arrangements worked best for minimizing personal cash invested?

Any tips for structuring a small gap partnership, private money arrangement, or equity split?

As a real estate investor, you first have to understand the risks most likely to impact you and then ask yourself how and why will this particular LLC arrangement or trust add protection to my real estate and your personal assets.  

In our discussion I mentioned how much these mentorships resembled multi level marketing, a comparison she disagreed with completely.

@Duke Davis  The three low rates were:4.25% fixed for 10 years then variable for the back 20 years (twice id that deal this year)4.75% fixed for 30 yearsAll 3 deals were arranged through a new home builder. 

If you try to arrange a seller credit outside the sales contract and out of the lender's view, I think you are playing with fire.