1. You should try and disable the collision that are not needed as this does save memory and helps process the game more.
2.The more collision points the more processing more is required. For example open up a sprite and add 9 points, it will then come up with a warning saying that it will make your game slower.
3. construct is very poor on mobile performance. To try and get the best result try not to add loads of objects into one layout and also don't add the physics behavior onto too many sprites as this causes a massive fps drop on mobile platforms.