Well congrats.. you made it to the Q&A. There's 100 views and no replies and I'm sure they're just rolling their eyes in terms of why you couldn't just search or bother to look at the General section where there's actually a sticky (Just saying).. If you're not tech savvy enough to learn how to root your phone then you're going to have a hell a lot of a tough time knowing all the terms when it comes to rooting.
-You can root your phone and use titanium back up to back up all your data/app or log into your google account and go to my apps and look at your dl history and dl them again
I'm confused of why you're shying away from keeping the note 3 and going to the m8 just because you're tired of touch wiz (am i reading that right?)
And in my experience, you should use kingo root to root your 4.3 device. There's pros and cons, misconceptions, and skepticism about the app. In the end it's your decision.
And here's a wiki http://en.wikipedia.org/wiki/Android_rooting
if you want to learn more about what rooting is.
Last tip of advice is looking through all the rom threads and looking at each developers work and features if you want to explore what you can do with your phone when rooted.