The commissions are usually paid by the seller (and built into the sales price so essentially passed on to the buyer that way but technically debited to the seller).

After the sale took place, escrow refunded the deposit to the original buyer, and I took some of the proceeds from the contract sale and added to the refunded escrow amount, essentially doubling his investment in one month, an incentive for leaving the escrow money with escrow another 30 days.

Did I expose myself to too much risk while he essentially incurred none?

Ideally we would get an attorney to draft up the specifics of our arrangement but things that we are unclear about include things like, who should take out the mortgage (both names v.s. the one who can get the better offer), what documentation is essential i.e. equality/partnership agreement.

I'm in the process of establishing an LLC but waiting for the final paperwork. 

I have a nice little spreadsheet of all income and expenses, plus paperwork for Hud-1, taxes, 1098 from mortgage company, etc handy for cpa.

We are essentially saying the same thing. 

Essentially do you have the resources for the rehab?

If they stay, you are getting, essentially, market rent without laying out reno costs.

@Hunter WolfeAs others have mentioned, you want to consult an attorney just to have the paper-work set up for what if scenarios"if the project makes $50,000...the money is split 50% / 50% or 75% / 25%""if the project loses $100,000...the partners are on the hook 50% / 50%""if partner A dies..the partnership is liquidated"etcGood luck with your investments