MurrayM:IntegerIsNumber: Opps sorry I meant 53001 :) its Vodafone.
Try clear your Google frameworks cache and Play cache. Samsung Apps uses Google play region setting.
Hope that help.
As for root issue you raised, if your phone has software issue then you can reset it back. But if it is a hardware issue then (water damage, crack screen, run over by a truck... Etc) you won't get warranty anyway. Also exploded phone might still be covered by warranty if it happens on its own. Either way hardware issue that makes the phone won't turn on (components failure, dead screen, , dead pixels or factory fault) will validate your warranty because it is not software related (from what I understand), use MHL cable and you can reset it from there.
As long you power the phone on (when you see Samsung logo) then you can always unroot it to get your warranty. :)
The odds of bricking is very small and the only way I can see you'd brick it is to corrupt the NAND flash via software flashing of third party ROMs.
The Google Services Framework already had an empty cache, so I cleared the Google Play Store cache. Unfortunately that didn't help.
I think I'll just wait till Samsung next update their Samsung Apps app and see if that fixes it. It's not like I really need to use Samsung Apps, I was just wondering why it had suddenly stopped working for me.
Hahahaha guess what now I got the same error as you do after the new Samsung update came through :) Great!