Most short sale approvals (FNMA and Freddie) will have an addendum requiring you to hold the property for 30 days; or for 90 days if you resell for more than 120% of your purchase price, and it generally comes in the form of a Deed Restriction. 

If you can't resell it, then you don't want to buy it at that price.

Granted this is on a nice lot and would be easier to resell.

I'd rehab and resell within 6 months.

He would typically put a few grand into it and then resell owner finance.

You'd buy an old house that needs renovation, you'd renovate it and/or resell to a foreigner or rent short term if the city has enough tourism.

You can work on houses that you purchase and resell.

I want to be able to buy properties at the right price and either rehab or turn right around and resell them to other investors, but n order to do this  I want to understand what would be the best way to do this so that everyone is protected and my investor receives a great return for his investment.

Then call the broker, let him know that you're reselling quickly, and ensure that you're comfortable that he knows how to handle it.

IMO, an option should be binding, especially when the buyer wants to assign the option re-sell the property at a mark-up.