You can't just say you are a business- you have to be open, have inventory, operating ect....with REI it typically means having purchased first rental, flip, done wholesale ect 

Just finished Flip #4 - sold without putting on market to a party interested in the project.

I'm evaluating lending $25k to a colleague who is been fix/flipping for some time.

Maybe flip a property or two to build up some cash reserves, or partner with someone.There's also a bit to be said about not over leveraging.

A higher end flip/remodel master bath we are currently working on.

One of the QI's on here can help you with the mechanics.And generally speaking, you cannot "flip" with exchanges.  

Long term I'm going to own large multifamily properties as well as dive into fix and flips.

I am a real estate investor who has flipped 3 houses in Southern Indiana.  

I found what appears to be a fantastic fix n flip opportunity that, at least at first sight, outperforms the 70% rule.

Neighborhood is full of retirees and has no rental comps....doesn't sound like a great place to buy a rental investment property......and Zillow estimate is WAY off from your desired rent and in a bad way, so even factoring in some "leeway" for Zillow being off, its not even in the ballpark of what you need..... so going to be hard to convince me this is a good buy...unless its a buy and flip, but based on your numbers it doesn't sound like that's any good either