MF deal structure with F & F down payment money

[Mike Enzwiler]

I'm curious if anyone has done this or is just too "off"   here goes:

I have the opportunity to buy a duplex with "Friends and Family" money for the down payment. The bank will hold the note in my name and it's a cashflow positive deal.  My thought is go 50/50 on it   50/50 on repairs, profit and ownership with the provider of the down payment.  

Am I lucky to have such a deal or am i giving up too much?     Thoughts please