Dude, EF is not going to generate lag unless your hard disk drive is almost filled(but in that case you could say any other additional/undesired program will do it as well) or you run EF. If it doesn't have an uninstall button you can just delete it(IIRC the first full version released for 1.6 had no uninstaller).
Your PC is not going to have any problem with that
. You can also use a registry cleaner program(I recommend CCleaner) to remove the registry entries of the recent deleted folder.