Straight up to your questions:
#1: I would suggest you check the Restriction
demo. It demonstrates how to control the edit/delete/create functionality of the widget based on predefined conditions. You can use the demo as a base to implement your business requirements.
#2: I believe that you can accomplish your goal wiring the edit
event and prevent the default action ( e.preventDefault() )if the current logged user tries to edit / remove foreign events.
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