If you're friend owns the other 75%, you're essentially along for the ride.

We both feel we could do this on a handshake but we feel that it is best to approach this in a business like fashion and put things in writing to avoid any possilble confusions or misunderstandings in the future.

The rest comes from old-fashioned follow-up calls and prospecting with SOI/past clients, old referrals and paid leads, and website traffic.

Wow, your journey with house-hacking sounds like a wild ride!

Should give you a rock solid start of how they would do.Good ole fashion enemy method!  

Also, I heard the suggestion of riding around in a bike & looking for vacants.

Our plan was grow in once city and see how it goes then move to the next for some diversification, if you plan on growing in a similar fashion I think you just have to pick your FIRST market and buy a good deal, I always learn way more going through owning a property in the area I'm looking.

I actually feel bad for the owners, because I can see that they may be wondering if we are taking them for a ride. 

They wanted to ride the wave and catch next big thing.

I think for now, I'm going to just do it the old fashioned excel way.