csc firmware changing in Samsung galaxy note 3

[Android Central Question]

I have a Samsung galaxy note 3 32 Gb SM-N9005 model from UAE.
Product code: SM-N9005ZKEXSI
Active and Original CSC Code: XSI
Firmware's CSC CODE: XSI
CSC Country: UAE/AE
Bootloader Version: N9005XXSGBQD5 / PDA Version: N9005XXSGBQD5 / CSC Version: N9005OJVGBPF1 / Baseband Version:N9005XXUGBPB1
Build Number: LRX21V.N9005XXSGBQD5
Build Date: Tue Apr 25 15:29:04 KST 2017
Changelist: 5438778

So can I flash any international firmware 5.0 and please suggest me some good internationally firmware which works great and makes my country change?
or can I root my phone after flashing new firmware and please let me know that not gonna effect on my sim card use of any country? BTW my phone is unlocked already I can use any other sim plans. right now

KINDLY ADVISE.