What you’ve done there is tried to remove something required by a metapackage (might be patterns-openSUSE-kde4).
The metapackages don’t actually contain anything useful themselves, they just depend on all the things that ‘group’ is supposed to have in it - the point being you don’t have to install everything manually, you just install ‘kde4’ and dependencies drag everything else in for you.
But if you remove something it depends on, it’ll also be removed - you can’t have a package without its dependencies. And, in turn, all the things installed by it automatically will try to run away too…
Solution? You can remove the metapackages but not their dependencies, and just try to keep track of what should be on your system yourself - this will be difficult, but not impossible. Your system will break, but you’ll probably learn a lot about it. In all honesty though, if you’re going to do that, you might be better off with a distro more like Arch.
More advisable is just not to remove anything that comes up with a list like that - obviously SUSE considers it an important part of the system, and they’ve been doing this longer than we have…