Clearly define what your goals are and you will have an easier time answering your own questions.Hope this helps.  

While they are not illegal, they are not well defined in their laws either. 5 out of 6 attorneys told me that forfeiture of a land contract can be resolved, but they can be contested because of the undefined equity.

as an investor, I know that 1) we are in a seller's market, 2) the investment property we sold is in demand from local investors, 3) I had 4 individuals interested in the property, 4) the "market" is reasonably well defined and homogeneous, 5) I knew exactly what price to ask for and what my membership wanted, 6) adding a broker in this case would add no value.

If he is going to invest 100% of project cost (as defined in my prior post) then you have no need for a 3rd party lender.That said, the following issues still need to be defined in order to make the call as to which structure (Loan or Partnership) works best for you (and him):If a Loan is in play:1.  

Your girlfriend should qualify as a "close friend with a clearly defined and documented interest".https://www.fha.com/fha_article?

In fact create a defined operating agreement on what is billed to who, and what should be done when something happens.

It's arguable more important to define the exit strategy when things are going well!

If they are unauthorized guests, then turn your property manager loose on them, repair the damage, and if necessary, bill the tenant that is on the lease for damages (sue if necessary).If these are squatters, then treat them as burglars.If you look up the definition of burglary, you'll find that generally, it's defined as the breaking and entering into a premise with the intent to commit a crime.My concern would be that your property manager is handling this like they would handle a tenant - in a "civil matter" as opposed to how they would handle a burglar - in a "criminal matter".It sounds to me like you don't have enough information to assess the situation.

Regardless, you may still want to have them sign actual leases with you at some point so that you can more clearly define the expectations for all parties involved.

One piece of advice for what its worth is to make sure you define your long term goals before buying your first property.