I’m very glad things didn’t work out.Lastly, Zach’s partner, Daniel, who seemed to be a more level-headed individual didn’t help matters any.

You and the other posters here have been generous in indulging me in this exercise of considering this "partnership" / BRRRR, but demonstrating that we can invest successfully on our own power before seeking out partners is not only my strong preference but just sound business logic.As a new investor my head starts to spin when I start to think about investing, and the many gaps in my knowledge reveal themselves: how to structure a partnership? 

A prudent investor doesn't seek quick riches through shortcuts.

I've Been renting all four rooms in my house out individually for about 10 months now.

Best bet would be a “partnership” with a monied individual looking for a high risk/high return passive investment with you providing the “active” part.  

Readers should seek professional advice.

When we built up the triplex, we set it up so that each of the 11 rooms can be rented out individually (all BR, except 2, have their own bathroom behind an electronically locked door).

Readers should seek professional advice.

Most foreign buyers are high net worth individuals who want to park their money there in a safe haven and they don't need BP.No restrictions apply to American buyers in the countries they'd generally want to buy, including those mentioned by Federico and many other popular countries.When it comes to Spain specifically, some more conservative banks will ask you for a 40% downpayment (that would be the maximum) but that isn't the rule.

The thread was intended to seek guidance on completing the deal, and even If I disagree with opinions I understand it doesn't make either side more or less valid.