Yes, go ahead and delete them.
If you do that, you'll want to re-run HJT after doing so, and delete the following entries if they still exist, otherwise you'll get errors on boot:
O4 - HKLM\..\Run: [YTDownloader] "C:\Program Files (x86)\YTDownloader\YTDownloader.exe" /boot
O4 - HKCU\..\Run: [SlimCleaner Plus] "C:\Program Files\SlimCleaner Plus\SlimCleanerPlus.exe" /minimize
O4 - HKCU\..\Run: [YTDownloader] "C:\Program Files (x86)\YTDownloader\YTDownloader.exe" /boot
O23 - Service: SlimWare Utility Service Launcher (SlimService) - SlimWare Utilities, Inc. - C:\Program Files\SlimCleaner Plus\SlimServiceFactory.exe