While he still kicks it back to a specialist when dealing with clients, he tells me exactly what we're looking at as far as costs and difficulty to repair / replace.  

Or we are all wrong and modern economic theory is flawed and no longer applies...

When I lived in Southern California I worked at a firm that designed ultra modern homes in Hollywood, Beverly Hills, Malibu and so on for a homes that sold between the low price of $10 to $50 million dollars.

What you need to do is make sure your replacement properties are equal or greater than the sold properties in purchase price and basis including depreciation.

The challenge comes in the case of a 1031 exchange when you only have 45 days to identify a replacement property and 6 months to close. 

We have a lockbox nearby for the tenants if they get locked out but it's 2021, I hoping there is a more "modern" solution. 

You need to look around... most big-box stores and larger window replacement companies offer free installation. 

There's no cleaner app that replaces the relationship you develop with a trusted reliable cleaner/cleaning company and their local handyman contacts.

I got a mailer from NRIA.org offering siding/roofing/ window etc. replacement under government grants.

You may not know the difference of the great area but look at the photos, and try to stick with: kitchen is modern, has heat and air conditioning.More time consuming but also free: call a couple property managers in given city; US census detailsPaying: rentometer; rentguide; insurify;