You can customize the event properties so certain actions (moving, clicking, etc.) are disabled:
http://doc.daypilot.org/calendar/event-customization/
You can also add visual hints on read-only status using custom HTML or active areas:
http://doc.daypilot.org/calendar/event-active-areas/
You should always check the permissions in the action event handlers even if you disable it (e.g. EventMove). You can inform the user about the result using the message bar:
http://doc.daypilot.org/calendar/message-bar/