I haven't had a chance to examine your capx. It need to be near exactly the same to work correctly (eg. event order/expressions). My suggestion is to just take my capx and make changes to it so it's like your game.
For bigger window sizes the only things you need to change with the events is the clamp expressions. Right now they are "clamp(something, something, 1000)", just change the 1000 to some number bigger than the width of the window. Also in event 56 part of the expression is "576*416", that is the original width/height of Sprite, and should be changed to whatever size you make it.