If he bail out, he would have to return the deposit plus 50k plus 30k renovations cost.

Typically the sponsor (you) still pay a preferred return to the investor and then if property makes more it evens out (called waterfall).

This will give you a good idea which deals make sense.Once you have a solid 15% or more cash on cash return you can find a money partner to acquire with you.Good luck and congrats on taking action.

Based on the returns being offered I would be extremely skeptical

In return perhaps I can be of some assistance with online marketing and video production.

In general, there are better returns on a duplex than a SFH.  

Cash on cash return comes back at 7.07%

I always ask for Tax returns for the past 3 years and 3 years of P&L, but often don't see that until You sign the contract.

But if you claim this on your tax returns, and your tax returns are used to qualify for future properties, then those depreciation items are added back to your qualifying income. 

Between 4% and 7%: It's up to your risk profile and whether you think you can make a better return in real estate.