And with the $50,000 from those two houses I'd buy a third house and get $25,000 down with an additional $500 a month cash flow and keep doing those until I ran out of cash.

Free cash flow will be split 50-50 once a yearIf additional funds are needed for cap ex, we each put in 50-50All equity build up will be shared 50-50, including; loan pay down, appreciation at time of eventual sale, and any 'cash out refinances' as we goPMPs original capital investment down payment will be returned to them WITHOUT interest at time of eventual sale or buying out of one partner or the other. 

Additionally, has anyone done a hard money loan?

Whatever that number is, ask for it in the form of non-refundable additional earnest money on the property in return for extending the contract.

If you want to take on additional members down the line, that will also affect your decision.

These are professionals with additional training and a stricter code of ethics.

I don't have experience with college rentals, but I would say get first and last month's rent in addition to the deposit up front.

Additionally, send a demand letter to the buyer for the earnest money if they failed to obtain approval within the required period in the contract. 

Additionally, I *think* my offer was suspect because I submitted a LOI instead of a PA, and I probably came across as a newbie on the phone, so they may have wondered if I would actually close.Lessons learned. 

Hard to say without additional information.