No idea. That is the problem with installing KDE apps under Gnome and vice versa. Both require lots of extra libraries/apps for even one small application to function properly under a different desktop environment. As to why those other apps were installed the KDE packager must have had some dependency in the system when they packaged, so you're stuck with it I'm afraid. There would be no easy way I know of to remove unused apps without possibly breaking the app you in fact want to keep.
As Kile generate pdf it have probably dependencies with KDE tools that deals with pdf, and as kile can browse you directories it probably have dependancies with konqueror and dolphin for this. If you have space on your disk it is not a problem and give you a chance to try Dolphin that I think is more advanced than nautilus.
dolphin and konqueror are recommended dependancies but are not required. In fedora they are not installed. So I guess that many other packages are probably not required...but it doesn't seem to bea aproblem, correct? (unless the size on disk..)