Raised capital from investors, what as must have's in your Operating Agreement?

[Brandon Chase]

We have an opportunity to purchase two multi unit properties. It will be seller financed. We raised the capital for down payment at 20%. What are the top 10 things to make sure are in the Operating Agreement between us and the investors? Such as, we have complete executing control, we decide when we sell, disbursements, refinancing the property, etc. What would be your must have's? 

PS. Yes, we are having an attorney write this OA up, we just wanted opinions to make sure we arent missing anything.