We have run in to numerous accounts of this.

Major issues are lack of parking, lack of elevators, leading to numerous unlived in units.  

You can surely hire a PM for one property, as long as you feel like the costs associated with it align with your bottom line, and cash flow objectives. 

Most importantly you seem to have an understanding that education is the foundation to build your investments on, and that will keep you from chasing shiny objects. 

My “reasoning” is based on two points1- the current system of property records filing in a million different jurisdictions with expensive title searches necessary for almost every title transfer and mistakes still being made can be made much less expensive, much faster, and much more reliable through migration to some sort of “blockchain” National registry.2- Numerous investments have been divided into, and offered as tranches of the whole.  

I also agree that RE appreciation is unlikely to match the last dozen years, but you never know.Where I am unsure we agree is that paying $450k to improve the cash flow ~$3k (your numbers but I expect my delta wold be similar meaning both my cash flow estimates would be worse than yours but both would be worse by the same amount not affecting the difference) makes sense especially if the cost of having the extra $450k is only 6% rate which is historically simple to beat via numerous investment options and hopefully no one is investing in RE for an expected of 6%.  

Most are going to want to lend on the rehab as it ensures the rehab to be completed,There are numerous ways to pencil it out in your favor though.It benefits to work with an experienced broker who can guide you through the process and put you into the best possible product and solution out there for you.

You need to look at it from the property owner's angle, and reverse engineer the problems & objections that are going to arise, such as:1.

Apparently has done jail time for numerous crimes.  

Seriously, looking back, my life is full of numerous examples of things that were labeled as impossible, or impractical, but I somehow managed to pull them off.