Buy a property with someone else's money and return profit

[Nick K.]

A family member is about to sell a paid off property overseas. He knows that I invest in rental properties and he would like me to invest his money for him. The plan will be to allocate his money towards the down payments of multiple rental properties that I would buy and add to my portfolio. He doesn't want to own the properties or borrow any money, he just wants his money invested. I don't know exactly what I might be getting myself into, so here are my questions:

1. Money transfer - What is the best way for him to give me the money in the first place without alarming the lender too much? Do I have to report the money he's giving me on my taxes?

2. ROI - I think it's not legal to guarantee return. Say a property returns $400 to $600 per month, I plan on returning 80% of the NOI to him. Is it legal and how can it be put down in writing? Investment contact?

3. Any gotchas? Taxes? Investing someone else's money? 

Thank you for pointing me in the right direction. I appreciate any advice beyond my listed questions.

Nick