[QUOTE=Arima] While I agree with some of these, I disagree VERY strongly about double clicking a group to edit it. I double click groups very frequently to open and collapse them quickly and easily, and in comparison I rarely edit them. It is also consistent with double clicking an event with subevents to open or collapse it.[/QUOTE]
Groups have the advantage of having a collapse button located at the left. Another solution is to press Enter, that already works for Events and Actions.
Enter edits actions and events,
Enter doesn't enter edit mode in Groups.