I've recently deleted Quicktime since I never used it anyway but now when I open After Effects, it warns me that some options will not work properly because I have no Quicktime. Is QT a really crucial part in AE? What does it do anyway? I don't use AE profesionally at all, only for things like a little motion typography to use in videos.
It's exclusively required for footage I/O. If you don't use any of that, then you're nmot missing anything.
We also use QuickTime for sending previews to external video monitors, but that's likely not relevant to you.