Partnering with a relative who will house-hack a duplex

[Ryan Mahoney]

Hello all.  I am looking to get into my first investment.  Currently, I am exploring the possibility of partnering with my brother on the purchase of a duplex.  The tentative plan is for the duplex to be in his name with myself as a co-signer (my credit is better but he can use traditional financing as a first time home buyer).  I would gift him the down payment which we agreed he would repay interest free when the home was sold or anytime before that point.  We would like to set it up where he can take a mortgage interest deduction as the owner.  He would be responsible for the mortgage and would keep any equity the property gains at future sale.  We would split the rental income on the other side and split any costs that relate to the rental side.  Any whole property costs such as a new roof etc. would be 25% my responsibility.  

At first glance I would appreciate any thoughts on this arrangement.  Not sure what the tax implications and mortgage deductions on a owner occupied duplex would be along with having myself on the note as a co-signer.  Additionally, because we would split the rent from the other side would this complicate our tax situation?  Would either of us be able to write off expenses and depreciation?  Would we be better served having him take the the rent and paying me 50% as the property manager?  Any other thoughts on this possible situation or better course of action would be greatly appreciated.