@Danielle Thomas, this all depends and comes down to what's stated within the lease agreement.

Make sure that paying on time is a requirement in your lease agreement!

US and Spain should have a reciprocating tax agreement.  

And even though virtually every sponsor agreement allows me to share investment information with others who might be advising me on it (especially when club members are bound by an NDA), I still ask the sponsor if I can share it, because it's a test.

Anything else that should be in our agreement?

Looks like I have some more homework to doHow about opening up single member LLC under myself and putting TOD clause to my wife in the operating agreement.

The second time i reached out he was interested in selling so I quickly sent him an agreement and got the deal under contract.

With that said, I would expect the lease agreement to be provided to verify the current income but that's about it. 

Renewal options are a better way for both parties to feel good about the agreement.

- If LLC isn't the best route, what other things would we have to do to ensure a successful partnership (e.g. joint bank account, partnership agreement, etc.)If you have any advice beyond these points that would be much appreciated!