Well, I live on the keyboard - using the mouse just takes too long (almost as long as it takes for me to properly phrase a post...)
To add an event via QS, I just type the event into the text box (dinner with inlaws on June 15 at 5pm) tab over and type event for "Create iCal Event" and then type the name of the calendar the event belongs to, and hit enter. Takes 15 seconds, and creates an event with the name of whatever I typed into the text box of QS.
Downside - I've just realized that the iCal module doesn't recognize times like 6:30, it will round it up to 7. This annoys me.
My biggest problem with the concept of sending an OF task to iCal as an event is that it's not how I see the workflow developing. Say I have a task to schedule a meeting. So I go, and schedule it, and maybe it takes a while, maybe it doesn't. But the total information about that meeting isn't on my computer - it's in my head - and I need to get it out of my head before I forget. It's ... counterintuitive to go to my computer, put a task for that meeting in OF's inbox and then send THAT task to iCal. In fact, I couldn't even go into OF to check the 'Schedule a meeting' task off with a good conscience until it was already on my calendar.
Please don't get me wrong, I do think the ability to add an event to iCal from another application is really useful. I just think that it's a functionality that should belong to iCal and not be cluttering up OF.