How can I tell if my International Galaxy S3 is suffering from Sudden Death Syndrome? If it is, how can I fix it?

I have a 16GB International Samsung Galaxy S3 (XEF) running the latest firmware, 4.1.2 (yes, the Premium Suite update, I was thinking that this would've fixed it but it seems not) with baseband XXELKB. Over the last week and a half, I've noticed my phone randomly freezing and/or restarting itself. I investigated further. At first, I thought it was to do with apps on the device, so I started recklessly uninstalling apps, to the point where I factory reset the device. No dice. Even with not a single non-stock app installed, it still managed to randomly freeze after a few hours of use. I went googling and discovered that my device is likely suffering from Sudden Death Syndrome, and I'm willing to think maybe I have that. Went through XDA forums, and found eMMC Check . According to that app, I have the affected 'insane' chip. There's a few quirks that I have, however: 1. Is this consistent with the Sudden Death Syndrome (SDS) that people are reporting? 2. Wasn't this bug supposedly fixed with the Premium Suite update? 3. How do I go about fixing this, for someone who has never rooted/flashed a Android device before? 4. How do I go back to stock firmware/kernel after it has been fixed by Samsung? Any help, even if it doesn't solve my issue, will be much appreciated. Cheers in advance.