here's the deal....you don't "need" to root it to simply customize it a bit. you can use a launcher to sort of do this. you can add widgets instead of apps to change the look on a homescreen as well. however, android phones all have a "skin" laid over the actual OS (except for nexus devices). samsung's is called touchwiz (htc has sense, etc, etc). if you were to root it, then you could basically run a stock version of android (people refer to it as vanilla) or you could use flash a custom rom. developers create custom roms with their own look and feel and their own mods and tweaks. if you are computer savvy and had experience jailbreaking your iphones, then it's probably not a big deal to learn how to do this and be capable of it. if not (and really even if you are confident) ten i would recommend playing around with it for a while before you decide you need or want to root it. you can do a lot just by playing with apps and widgets to customize it. there are icon pack apps in the play store that replace the actual icon with others. there's an app called elixir 2 that i use to create a widget that is actually a 7 wide icon bar so i can place 28 apps on a screen. you'll have a decent learning curve and i would suggest spending a lot of time on google and youtube. most of want you want to do is out there. i don't think that the issue with your post is that nobody wants to help. i think it's just that i could literally type ALL DAY here and give you some tips and tricks, but it's already out there on the web. i will tell you this (because i found it very confusing). when you use a launcher, you can't use the samsung stock widgets. the launcher more or less replaces the touchwiz UI, so you will need to use the widgets included with the launcher or download other widgets. for example, if you install and launch ADW launcher, you won't be able to use the samsung weather widget. i tell you this because the first time i used a launcher it threw me for a loop.
rooting is a blast and the customization with root access is endless, but if you are completely unfamiliar with android, then i would at least get to know it before i rooted.