Flashing Stock Android ROM from another country I purchased my SM-A520F from UAE. I am currently using the phone in India. 

All Samsung Mobiles sold in UAE have VOLTE disabled by default, and hence my phone do not have it. However, majority of the 4G carriers in India use VOLTE and this causes problems that are not minor.  

Rooting the phone will probably void warranty. I was told that I can flash stock firmware for this device released for India without having to root. 


Will this void warranty?
I contacted customer support of Samsung UAE and they told me it would. But I dont believe them since sources on the internet say otherwise and I won't be rooting the phone. 
If I were to go ahead with this, where can I get the official firmware? Is there any option to download this from Samsung website?
What is knox counter? Will I be able to do this without "tripping" knox?
Once I download and install stock firmware from a different country from a  website like Sammobile.com can I still receive OTA updates?
After flashing a firmware downloaded from a third party website, how safely can I use applications that use sensitive data like S Pay and mobile banking applications?


Thanks a ton in advance.
Yes, it will void the warranty; 
Hard to say, some Samsung firmwares are available "officially", some are leaked, and some are not available at all. XDA forums for you device are the best place to look; 
KNOX counter is a way of checking if you phone is or has been modified, in theory flashing a stock ROM will NOT trip the Knox counter; 
Probably; 
If you are stock, you are stock, the source of the image isn't relevant since the image will be digitally signed.... 


The real issue here is the hardware/radio differences that cannot be edited or flashed, it likely will not function right, that information is protected and tied to the device, flashing a ROM does not change bands or network connectivity of the hardware, but it does change the radio firmware which can cause a mismatch of hardware capability to radio firmware preventing connectivity.