(not endorsing them but can cite their merits) It enables a Landlord to get a just & fair snapshot of the creditworthiness of a potential tenant.

We may feel, well we're doing a good deed, by bending over backwards to help our tenants by picking up the rent, or little things, but in actuality you are not helping to make the tenant be a responsible individual, but instead are being an "enabler"  to rely on others to do this or that for them.  

If the powers that be need to contact a property owner, they can simply query the database.

I would like to take over the mortgage payments of a seller is there a document that enables this for me to provide to the seller? 

Your brokerage will typically have a pretty good database of open listing and also likely the RLS.

I have not built a Buyers list, Yet I was thinking of the Same issue.I decided the most effective cheapest and Custom way is to Hire a Database programmer.

I am looking for a CRM type system similar to a database. 

When Airbnb sees activity it interprets that as a host being active and the algorithm then gives more confidence to the accuracy of your listing.4) Enable instant book.  

Also, if you make an insurance claim, it goes into a database and going forward, both you and the house will see the insurance costs rise regardless of the carrier you change to.

So building it to enable landlords to charge separately, at least in my area, is simply inefficient.