Save the event once. The Google Calendar invitation writes itself.

Yes. Google Calendar sync is available on all plans, including the free plan. You can push events to Google, pull events from Google, or sync both ways at no cost.

Outbound, the entry is written when you save the event. Inbound, Google sends a push notification to Event Schedule and the change is read within seconds. An incremental sweep every fifteen minutes is the backstop, so a notification that never arrives costs you a quarter of an hour rather than the change itself.

Yes. Each schedule picks its own Google Calendar and its own direction, from the one Google account you connected. That lets you keep a band schedule, a venue diary and your own week in separate calendars.

A recurring event is written to Google Calendar as a single entry at the series start, not as a Google repeat rule. If you want every date of a run to land on a calendar, the schedule's iCal feed is the better road: it publishes one entry per date for the next ninety days, and a subscribed calendar re-reads it on its own.

Whatever you told it to do. Each schedule has a policy for events deleted in the connected calendar: keep the event here, mark it cancelled so guests stop seeing it, or delete it here as well. It defaults to keeping the event, because that is the choice you can undo. Delete has one brake: an event with ticket sales on it is hidden instead, so its sales records survive.

Not on their own. Connecting starts the sync from that moment, so events you save afterwards are written out and the ones already on the schedule sit where they are. The re-send button on the schedule's calendar tab is what backfills them: it walks every published event and puts it on the calendar the schedule points at now. It is owner-only, it needs a direction that pushes, and it runs in the background rather than making you wait.

They stay. Disconnecting closes the notification channels, clears each schedule's direction and calendar choice, and drops the tokens, so nothing further is written or read. It deliberately does not go back through Google deleting what it wrote, because that is not a decision worth making on your behalf. If you reconnect later, use the re-send button to bring the two back into step.

Yes, and that is a separate thing from sync, with nothing to connect on your side. Your pages offer Subscribe to all events from your schedule, in the Add to Calendar menu and beside the email sign-up. It is the schedule's live iCal feed, so Google Calendar adds it as a calendar of its own and keeps re-reading it: a date you move moves for them too, though Google can take several hours to notice. It carries your public events, with each date of a recurring event for the next ninety days, and it asks for no email address and no account.

Yes. A selfhosted install uses its own Google OAuth credentials: create a client in the Google Cloud Console, add your callback URL as an authorized redirect URI, and set the client id, secret and redirect in your environment file. Push notifications also need your install to be reachable over HTTPS. Full setup instructions are in the selfhosted documentation.