Wow... 82Mo for the capx ? I bet the image is rather large in fact ! Maybe you should use smaller resolution ? I'll take a look after download, but this isn't a good sign... How much VRAM does your program take ?
When something is lagging/not working right, try to use the Debug Layout feature, as there is a tab with Performances Profiling, helping you understand where the bottle neck is.
EDIT after DL : yes, try to cut your image in multiple pieces. This is the origin of your problem here. After all, there is only 3 objects for now, and I'm already at 40FPS (bad computer but still)