At what point will i need a lawyer ?

Let the current owner deal with getting that from the tenants, as they should be signing it as well.When we bought, the owner said that they didn't want us calling or emailing the tenants, so we just showed up one early evening with cookies to talk to them and introduce ourselves, (that just happened to be how we could get around what they were saying).On the matter of security deposits - The recommendation I got from my lawyer was to have the owner pay out the current interest back to the tenant. 

Spend the $$ on a real estate lawyer so the letter of the law is followed and your "friend" is sent on his way most expediently.

Is it all solely documentation drawn up by a real estate lawyer and we're good?

@Sandy SawyerI think this may be a legal question, and seeing as though giving out legal advice without a law license can get me into trouble, you might need a lawyer to help you figure out the best way to file your individual series in accordance with the new legislation.

I'm no lawyer though. 

Did you explain to a lawyer what you wanted to accomplish he was able to put together a LLC and other legal documents to spell out rules, responsibilities, earnings allocations, etc?

While I still say go speak to a lawyer, he/she will be telling you things that come straight from this easy to read pdf link.

Please note that I am not a lawyer, but with a policy for short term rental you should be similarly protected. 

In my email, I told her and her lawyer that we have not settled yet, it's still her building and she need to get the oil delivered.It was a commercial property and we later found out her occupancy numbers were also fudged.