1. Active areas that specify the "action" property will not let the mouse click event bubble to the underlying event and the event click action won't be fired. You'll need to leave the "action" value unspecified.
See also:
https://api.daypilot.org/daypilot-area-properties/
2. If you use active areas that cover the whole event you won't see the styles applied to the event. You'll need to add custom CSS that applies special styling to active areas that are inside a selected event.
The selected events are marked with ".scheduler_default_selected" class:
https://doc.daypilot.org/scheduler/event-selecting/