Sounds like you need some kind of freeze/thaw mechanism when you know you'll be firing a lot of events. Then if events arrive while the UI is frozen, you don't act on them until it's thawed (and you act only once). Is that the right way to go?

I think you'll need to do some action per-event, but things like sorting the items can wait, right?

You shouldn't need to do much sorting anyway, if you can use something like the Arrays.binarySearch() method when doing inserts and keep things permanently sorted. Then only user-requested sorts need action...