The final cleaning is done by the adult children and the wife does the invoicing.

That way the water company meter gives you a reading and you have an accurate submeter reading to break out the invoice and use that. 

My 2021 renewal invoice was for over $900/yr.

If, as an Owner, you have the PM make your mortgage payments, insurance, property taxes, ongoing service contract invoices, maintenance, repair, and capital improvement expenses, rental income, parking income, laundry income, insurance claim income, and anything else relating to the property, it greatly simplifies your income tax filing with clear and accurate records.

Fill all of your invoices/bills after they are paid (and write paid on them) in your tax folder. 

Ideally what I am envisioning is a platform that the group coordinator could enter each members name and a contact email or phone number and they would then get an invitation by text or email to join the group where they could pay the reservation fee, final invoice, and we could share all check in info and other communications.

Enter a maintenance request, assign a vendor, attach a fake invoice.

Will you get a copy of the vendors invoice or do they simply put it on their own form?

I never get the receipts or invoices for scope of work unless I ask her directly; I expect a good property manager to send receipts of repairs and keep me informed of any repairs and when they’re scheduled.

How do I calculate the tenant's monetary responsibility of wall damages which required drywall repair and painting from the total invoice cost?