Welcome to BiggerPockets Joshua and best of luck investing!

How about using 3rd party management? 

And there was no chance in hell that my investors would not get their money back: I had confidence in my deals and my ability to manage contractors and enough of my own capital as a risk buffer.

Investors base their purchases on potential, but appraisers base their numbers purely on formulas and comps.

This is not something you will get online you need an attorney to draft documents and it is just a matter of whether you draft them or their attorney drafts them

I Would love to hear peoples experiences of renting a room in Vegas, what sites people used and what to look for when accepting a potential house mate?

@Patrick Schwebke Yellowbird (local JAX company) has a facebook group that's very active and I think has monthly meetups, or at least they used to.

How did you find this deal and how did you negotiate it?

Get real clear on where you are and where you want to go.

I'm pretty active in Brooklyn and have closed multiple multifamily buildings, with the most recent happening a few days ago 11/26 @ $1.55M.