In my application I needed something like a particle system so I did the following:
While the application initializes I load a UIImage
laserImage = [
I'd recommend starting over using OpenGL ES, there is an excellent framework called cocos2d for iPhone that can make this type of programming very easy and fast. From a quick look at your code, you're lasers can be remodeled as CCSprite which is an easy way to move images around a scene among many other things.