Windows 8 Dual-Monitor
Quick update, I found a solution. Just took a bit of help from Microsoft and HP. Apparently, with a HP Compaq L2206tm, I have to go to Windows 8 Control Panel —> Tablet PC Settings —> Setup, then tell the system which is my touchscreen. Touch input now registers on the correct display.
Only problem now is that because I play GW2 client in fullscreen, any desktop input on my extended display minimizes the game. Still waiting for a solution from Microsoft on that one I guess.
Put your window type to Fullscreen Windowed. It will still be fullscreen but wont minimize when you do something on a second screen. Can even drag windows on top of the game screen then (overlays etc)