Some accounting software (like QBO) let you attach documents in the transaction. 

Did not attach the link.

They have all said that they don't add any value for an owned system like mine, which seems wrong, as there is a lot of expensive equipment attached to our property. 

If it really is 8 units it will not be good, there will probably be a ton of deferred maintenance so the low purchase price comes with strings attached that you will have to fix a lot of things to avoid being a slumlord.

After a few years he'll lose the emotional attachment to the properties since he'll only have been getting payments for mortgage and you might be able to discount the note at that time.  

Assuming the lender is unwilling to transfer the deed, or has a penalty attached to transferring deed. 

PM is fine if you don't want global sharing.I've been using Airtable (which is excel like but let's me attach receipts to rows).  

We are currently negotiating on three properties and will hopefully have a couple under contract soon.Also, I have to add...when I left their office to drive back to the airport, my rental car had a flat tire and without even hesitating, both Joel and Scott jumped in and changed my tire in record time (photo attached).

As used herein “additions, improvements, or alterations” includes, without limitation, lock changes, painting, replacing fixtures, installing wallpaper, attaching shelves, installing curtains or shades, or other permanent or semi-permanent changes to the Premises.

It was great because it has seasoned me, in many ways, to make quick "Go/No-Go" decisions, to not get too attached to potential assets, and to understand what criteria investors typically look for.