I had a similar situation to you.
I dropped my phone on the sidewalk, and while there was some physical damage to the side of the phone, but the glass wasn't damaged at all. However, the actual AMOLED display under the glass actually died over a span of 24hrs, slowly, in a circular pattern, starting from where some of the physical damage was.
Sent directly to an authorized repair place, they deemed since no glass was broken, screen shouldn't have died, so replaced it 100% free, even fixing the actual damage to the exterior as well. All under manufacturers warranty.
As long as you get the phone back to stock, you should have no problems. I didn't even have root, so I'm sure if you get rid of it, you'll be fine.
I am from Canada though. Can't really see that changing anything though.
Good luck with the replacement!
Sent from my SM-N900W8 using xda app-developers app
My trek through cellphone history:
Nokia 252 - Green
Mitsubishi Trium Astral - White
Samsung Omnia II
HTC Desire Z
Samsung Galaxy Note 1 - 16GB - White
Samsung Galaxy Note 3 - 32GB - Black **Surprisingly, under warranty, they even fixed the physical damage I caused. Go figure...**