OK. Lots of newer users here so let me touch on a few things that should well translate from the NC.
1. uSD classes: seems to matter little when using apps. Seldom are the speeds accurate anyway. Use reputable brands. Sandisc one of the best.
2. Never format uSD in your device. Always on your computer. Don't use Windows format. Often creates problems. Use this
. Free and never failed me.
3. Root is optional for the NT right now. Certain apps require root access BUT untill a workable recovery scheme is devised I would recommend sideloading. Always unmount before removing. Yes, OTA will work and GApps will update.
4. I've not seen yet a reliable method of re-partitioning the eMMC for the NT (might have missed it if so) therefore sideloading would appear a workable plan for now.
5. If the hurdles can be overcome (and it is early yet, people) to achieve root + recovery many options will open but the NT appears pretty darn good as it is. Patience is a plus.
6. Search function and Google search is your friend. Xda is phenomenal but there are many other forums and many senior members post/read to several.
7. Research what you want to do before doing it. God knows I learned that the hard way myself!
8. An app called App2SD can help you moved apps that will function from the uSD and clear space on the eMMC.
9. Did I mention read and research?
10. One last thing...it's always good form to click "thanks" when assistance is lent.
The senior people on here once were where you are now and are happy to lend a hand. Read the Xda rules and all should be well.