Even if you have wings, Stoned will easily kill you with fall damage. Frozen won't.
The Blindfold and the Magic Mirror will not protect you from Stoned, but a Pocket Mirror will.
Pumping a liquid into a waterfall generates infinite liquid.
Most blocks that hold pools of lava in place will be destroyed when you mine them. By the lava they were supporting.
The Destroyer can fly, but only when you can't see it.
A chest and the blocks below it will become completely indestructible if the chest has something inside it.
You can store chests in chests.
You can use a chest to contain a Piggy Bank containing a Safe containing a Defender's Forge containing items. You cannot do this with only chests.
You can have a Piggy Bank containing a Safe containing a Piggy Bank containing the Safe containing the Piggy Bank containing... you get the idea. In fact, you can physically store a safe in a piggy bank.
Inventory management in general.