Root [International] Installing a Custom Rom

[sershh]

Hi, I downloaded this ROM

[Stock Official Firmwares] I9300XXELLC (4.1.2) - Spain (PHE) [11-01-12]
I9300XXELLC
Base Firmware: I9300XXELLC (4.1.2)
Region: Europe
Country: Spain
Carrier: Unbranded
Build Date: 28 December 2012
Modem: XXELLA
CSC: PHEELL3
Change List: 764725

I succesfully installed this ROM with Odin in my previously rooted Galaxy S3 (international). Everything is fine


but the question is:

Would I be able to flash this ROM using Odin without rooting my phone?
What happen If I dont change the CSC to the one of my region?


By the way this ROM works great.
Thanks.

 

[Metroid Prime]

Moved to Samsung galaxy S3 (International) All Things Root.

 

[Shotgun84]

As that is official stock firmware you could've flashed it with Odin without rooting. There's no need to change the csc. The csc is used to identify a phone for updates via ota and kies but to get these updates your firmware would also need to match. So if you changed csc there would be a mismatch so you wouldn't get the update anyway. Changing csc will also wipe your phone.