Is it possible to install the Quicktime backend without getting the frontend?
Sadly there isn't really an alternative, many dll's coming with QuickTime are needed by programs like LightWorks or Premiere and After Effects.
You can probably delete a portion of the QuickTime installation but in the end why bother?
Just don't let it take over any of the file associations and disable the auto-updater so it doesn't nag you whenever there is an update to QuickTime or any other Apple product. Then it wont bother you in any way. You can also delete any icons and start menu entries if you dislike those aswell.

Though generally its advised to have QuickTime installed when working with video even if your tools don't need it. Its a widely used player in the Apple Ecosystem and the .mov format is still very popular in video production even on Windows. While you don't need quicktime to check .mov files it's the most reliable solution there is.