Expect the remodeler to measure the alcove, look at the existing valve, and check the floor where the tub sat, since water often collects unseen beneath old tubs. They should tell you whether the valve can be reused or should be replaced with a pressure-balancing or thermostatic valve, and whether the drain needs to shift for the new base.
Permits go through Wareham Inspectional Services online, and the town mails the building permit to the applicant. Make sure the card ends up posted at the house, not in a mailbox at your year-round address, because inspectors who don't see it leave and charge a re-inspection fee. The plumber then arranges the rough inspection, which Wareham holds on Tuesday, Wednesday, or Thursday.
In an older house, removing the tub can expose cast iron drain fittings or a patched subfloor. Ask the remodeler how they'll tell you about those findings if you aren't there, such as photos sent the same afternoon, and how changes get approved in writing.