[T-Mobile Galaxy Note 4 Android Development] iunlock:
No worries. Here's the order in which I flash a ROM when jumping from different firmwares: (Of course it's pretty much on par with the directions on the OP).

Check List Before Flashing:

Download all the files that you need: V17x ROM file, Stock ANK4 firmware file, Chainfire Auto Root file, and TWRP file.

Check your md5 sum for the files you can. Make sure they match up.

Double check to make sure you have the correct files for the Chainfire Auto Root and TWRP.

NOTE: Never factory reset or wipe your internal/external storage from within TWRP as it does something weird to your phone and will cause boot loops and a nightmare of issues even if your phone boots up after flashing a ROM. Just follow the directions to a T.

Next...

Manually Back-Up the things you want to keep on your internal storage one by one. (ie...connect your N4 to your computer and literally start drag&dropping folders/files you want to keep. Make sure if you're backing up program app files and such that it doesn't contain anything in there that will contaminate your new set up.----> Don't resort to any back up programs such as Titanium Backup etc....Don't. Do Not. It's trouble waiting to happen. You don't want to get your old program files/data all mixed up with the new stuff you're about to flash. Especially them being on two completely different firmwares.) Note: Everything on your external SD Card will remain intact so no worries there unless you want to just back that up too, but not necessary. Just make sure you don't obviously nuke that (accidently reformat the card) from within the phone and/or in TWRP.

Factory Reset from your

phones

setting. Just nuke the darn thing and wipe it clean.

[*]Connect your phone back to your computer and drag&drop the FK-V17x ROM file to your internal storage.

Odin Flash: Stock ANK4

Odin Flash: Chainfire Auto Root

Odin Flash: TWRP (This is the .tar file, NOT the .img file as the .img file won't even show up in Odin. If you want to flash the .img file you can, but Odin'ing it is much more convenient while you're Odin'ing everything else anyway)

Boot into TWRP (into Recovery): -> Go to Advanced Wipe and Check ONLY the following: [Dalvik - Cache - System - Data] and SWIPE to complete Advance Wipe

*** DO NOT CHECK internal or external storage. ***

Flash the FK-V17x ROM file that you dragged onto your internal storage earlier. Let it do it's thing. Once finished, Reboot.

Once rebooted, let your phone sit for 15 minutes. Don't touch anything. You'll see the set up screen, but just turn off the display and let your phone settle.

After 15 minutes, set up your phone and once you get to your main Home screen, you can reboot if you want or just fly from there....I usually just reboot it again for the heck of it. Note: When setting up your GMAIL, it'll give you the option to back up/restore your program data files and such....I usually always keep this "unchecked" because if you leave this checked, it'll start auto downloading all the stuff from the previous set up. The whole point of leaving it "unchecked," is so that you can start CLEAN and remain CLEAN. This is completely optional, but I always do not check that part.

Hope this helps. Good luck and keep us posted on how things go!