I took his processes and his forms and have integrated them into my processes.

Not for payroll (no employees) or for billing (not getting paid by the hour), so I don't care if it integrates with quickbooks, for example.Just looking to 1) know what I'm spending time on 2) maybe establish prof RE status or as evidence that another venture I'm trying is, in fact, a thing I'm trying to run as a business even though it is currently losing money and hence might be viewed as a hobby.

Asset protection and tax strategies should be integrated. 

In addition to regular communication, we can set up automatic reminders for team members, integrate various forms, and even connect it with other apps.

Integrity and reputation.

Then upgraded the inside of the units with appliances to stainless, changed cabinet fixtures, new doors locks, lockings mailboxes, bathroom fixtures (lights, vents, vanities, medicine cabinets, etc), and applied high gloss to the hardwood floors.

I personally use Hospitable for hosting, it integrates with my Schlage Encode lock and automatically generates door codes.

If the vesting integrity changes, you are risking this as well. 

With that said, I don't think that special websites are needed here, especially if they don't integrate with PMS software.

I would definitely recommend wholesaling as a good way to further integrate yourself into the way things work.