I have made a lot of money in RE (8 digits) and have not purchased in over 2 years.  

Maybe I should sell all my assets and buy Bitcoin at $11,000 a piece today.

A property manager can be a great asset for regular check-ins and updates.

There are asset protection companies who make lots of money off this - I talked to one who said it's $13,000 (for 4 properties) to set up layers of protection then annual fees after this. 

Create a digital folder for lease agreements and tenant records.

If you have substantial (usually means 5 digits or more) donations, tax planning opportunities can get very complex.

Or in your case, maybe even change classes of property and use what's known as a consolidation exchange to combine the sales into a larger asset like a multi-family or commercial property.

You will always have to be an asset manager of your property manager as your property manager is not a mind reader for your investment strategy decisions. 

The reason people do sub2 is to get around this requirement and not notify the lender they are transferring the asset.

That gives an investor a real asset to collateralize and it gives them incentive to not let the buildings dilapidate at the end of the lease.