Application Uninstalling Question.

So I've installed a few applications here and there that haven't really worked like I wanted them to. I recently installed Parallels and I hated it. I deleted everything I could find but when I search "Parallels" in my finder a bunch of other stuff appears. Is that all related to Parallels, is it okay to delete them all, or not? The only reason it bothers me is because my computer used to shut down literally 5 times faster than it has been since I install Parallels. I think maybe that was the problem and if I delete everything I can find related to Parallels it will shutdown faster. Any tips or ideas?