Rooting questions

Hi, first time Android user and newbie here with a few questions about rooting the Nexus 4. First off, what apps can I use to back up all my data (app data and settings, most importantly) and is easy to transfer back to the rooted phone?

Also, I'm kinda confused on this: if I root my phone but keep the stock 4.2.1 rom, will I be able to update to the next version of Android (possibly 5.0) once it comes out, without much hassle? Thats one of the biggest things I'm worried about.

Thank you!