Changes required within the calender plugin

Hey all,

I need some for me very important changes within the calender plugin:
- Each group should only be able to create one event;
- The event name should be automatically be the same as the groups name in which the event is created;
- the widget should display also past events. In best case, the user could choose between upcoming or past events or there could be an extra widget for past events;

Can you support me with these needs?

Thanks for your response,
Mario