I'm curious how you would handle managing when working a full-time job in the military.

Upgrade to a commercial-style stackable setup that can dry faster (30–45 minutes), hopefully fitting in our existing laundry closet without extra electrical work.Any recommendations or specific brand/model suggestions for handling this high-volume, semi-commercial laundry?

You most likely would not get access to them until disposition of the entire property/partnership interest of not handled correctly.

Is this all handled by the PMS and then routed to the guest by whoever is the primary host?

You could form a month to month lease with a just a days notice to vacate so you could end it as soon as you get your license ready to close, the seller might be open to it.https://www.hostaway.com/blog/rental-arbitrage-joshua-tree/Or, you could continue to list on the seller's Airbnb and you could become a full-access co-host on their account - handle all communication, pricing, etc.

It's important to ask yourself, and be honest with yourself, how you would handle managing tenant situations if you were to become a landlord.

Please kindly help to handle this the best way. 

The least states:"Tenant shall pay a "late charge" not in excess of five (5%) percent of the amount in arrears for each month the arrears remain unpaid if any Rent is paid more than ten (10) days after the due date thereof, to cover the extra expense involved in handling delinquent payments.

I use Steadily in FL - feel free to shoot me a DM and I will link you with my contacts there that handle all 50 states. 

Alyssa Bunting handles all of Williamson Count.