All four attached dumps are verifier enabled and flagging atikmdag.sys which is the ATI/AMD video driver. If you're on the latest Windows 8 drivers for your video card, I'd recommend rolling back a version or two to ensure it's not a latest driver issue. If you are NOT on the latest, definitely update to the latest video card drivers.
Remove all of your Asus utilities you have installed, one of them (AsUPIO.sys) is dated from 2010!!! - ex
Asus PCProbe Utility
Asus Charger Driver
They are known to cause a lot of BSOD issues.
SYMNETS fffff880`03c00000 fffff880`03c72000 Tue Apr 09 19:24:13 2013 (5164a31d) 0006fc1e SYMNETS.SYS
SYMEVENT64x86 fffff880`03c72000 fffff880`03caa000 Wed Aug 22 01:33:18 2012 (50346f1e) 00036d33 SYMEVENT64x86.SYS
I notice you have Norton and I am keeping a close eye on that. If you're still having BSOD's after removing all Asus utilities, Norton goes next:
Replace with Microsoft Security Essentials.