Cancel any time: in your dashboard open Account & billing and press Manage billing. Your screen stays on until the end of the month you have paid for.
More than one location: yes. Each TV is its own screen at $49 a month, with its own cards and hours. Add a location from your account page.
Invoices and your card on file are under Account & billing → Manage billing.
When the free days end without a subscription, the screen shows a short message; subscribing turns it back on within about a minute and everything you set up is kept.
Billing, cancelling and more locations
How business owners cancel, add locations, find invoices, and what happens when the free days end.