Default Cross ROM Flashing

I am trying to find solid answers on this before I do it, but can't find any evidence it will work, and without issue. I just want to gain my T-Mobile wifi calling, and be able to use IPv6, but the ROM that my Note 3 came with, does not allow any of this (APN protocol is perma-greyed out and of course no wifi calling).

So here's what I have: Mexican N900W8

The ROM I want to flash: N900T for T-Mobile. Stock ROM.

Can I just simply use Odin and just flash it without rooting or anything since both are stock ROMs? Or do I still need to root it?

Also, if it will just flash right over, will my phone identify itself as a N900T and get over the air updates for T-Mobile, or will it ID itself as a N900W8 still, and possibly have future update problems?

Lastly, will all the other hardware work fine without issue? Wifi (most important obviously), NFC, etc?

Thanks.

I tried looking for this kind of cross flash but could not find anything whatsoever concrete that re-assures me this will work.