You can just install a launcher over TouchWiz and set the Launcher as default. There are tons of them available these days and it won't void your warranty like rooting it will. Plus, you can always try multiple launchers until you find one with an interface you like, and since most of them are free, there's no downside. You could start with something like Nova, I'm using Buzz Launcher now because they have tons of different Homepacks (the graphical part of the launvher) that other people have designed and are free to use. You can basically change the look of your screen every day for 30 years and never use the same one twice. TouchWiz will still be there, it just won't be visible.