Soliciting Advice for New Mobile Phone and Carrier

[brutal]

On my Android Tablets, I have 'Rooted' them, partly for the limited memory issue you describe.
The 'Roots' I have done allow me to move 95+% of the app's executable to the SD Card, and then run them from the SD card.
For about 98% of the apps I tried, it works fine. The other 2% either won't LET me move them, run too slow from the SD, or crash.

The other thing I liked about rooting was, providing you look around, you can find a suitable ROM Image without the Bloatware (pre-installed apps eating up ROM that you don't want).
Then you can selectively install what you want.
Again, this helped free up my Device memory.

I plan to do the same for my new phones, providing I can find a reliable image.
I'm told Verizon locks things down a bit tighter than the factory Samsung devices (Ex: the bootloader is hard to access)

Watch out for KNOX on VZW Samsung devices. Blow the e-fuse and your warranty is gone.

Looks like there's a new app - Kingroot - that is a one click root that's working on current model firmware but I haven't finished reading through the threads yet to see if it's KNOX safe.

I doubt you're going to find any way to unlock the bootloader on any current VZW Samsung device. Best you're doing to get is root. You can get around the bloatware with Titanium backup, xposed framework, etc. There may be others, I haven't looked lately. root thread on xda http://forum.xda-developers.com/show....php?t=2784860

[blacklabel]

I'm trying to fathom what causes a person to go through 80GB of data? Video streaming?

When I was still with Verizon and had their grandfathered unlimited, I went through 115 one month. That was purely out of spite though.