Assumed nothing could possibly go wrong in the next 5 years what you want when you look at an investment property is to know the current rental amounts, specific expense items, and conditions of the building, grounds, and mechanical systems.  

The conditions on the ground going into the project may not be the same as when you complete!

This property had significant potential for value enhancement due to its location and condition.

You can pick up a duplex in decent condition in a C-class neighborhood and hit the 1% rule

If you keep it as an investment property, a lot may depend on your location and condition.

Or, rent growth is assuming 2020-2022 type market conditions.  

You’re not overleveraged, so you’re in pretty good condition to ride out a downturn.  

If I put myself in the shoes of the outside partner/investor friend, I would be very concerned because: 1) unclear and/or potentially conflicting business plan, 2) even with clarity in the BRRRR business plan, unclear in the viability of pulling it off with these market conditions, 3) the chances of dispute seems very high, especially if you're going to live in. 4 years ago, I went through a  similar thought process when purchasing an investing property with mainly my family money, while considering an outside investor to rehab for higher STR ROI... 

I base my rents on the condition of the unit and the competition. 

Market Conditions: South Florida has a dynamic real estate market.