They can be stacked, and they won't break when they're thrown. However, they can be destroyed by one of Mickey's Bounce Attacks. Jump on it a couple of times to gain extra height. Springs can be picked up and carried to where they'll come in handy. Use Mickey's Bounce Attack to make it freeze, then use it like a normal block.
Buttons work only as long as they're being pressed down.
These items have upward-pointing arrows on them. The arrow will then point down. If you need to turn the switch off, simply have Mickey jump on it. As you search for the Phantom and the crystal, you'll find special items hidden in each level. Some are hidden in treasure chests, which you can break open by throwing them or by using Mickey's Bounce Attack.