Did the sponsor receive equity ownership in the property, or did you employ a different method to compensate the sponsor for his/her support in the deal?

@Brie Schmidt has a great method for incentivizing the PM so their goals are aligned with the owner's.

Take the time to learn how plumbing works, how an electrical system works, what components go into a roof etc.  

This would come in handy.Because of the financing we found, we would be doing all work ourselves except for the plumbing, electric and HVAC.

I have used that method several times. 

I have been trained in Structural, Electric and Plumbing.

Should I just loan the funds to the business at a certain interest rate, then that gets paid off first before we divide up the profits 50/50 or is there some other method that makes more sense?

Learn how to be a landlord and how to fix stuff around the house- basic plumbing, electrical, etc.

Can you share with me some of your thoughts and experiences using this method? 

Therefore, your most time efficient method might be to send your listed expenses to the seller's agent or closing attorney and announce in clear words that you will sue if you don't get fully reimbursed and the EM released to you in 48 hours.