1. Because I am an INTP and only care about what is theoretically in the box and need no actual confirmation, I wouldn't need to open a box.
2. I would ask the first box what the second box would say about the first box's honesty, then go from there.
3. I'd open the box that doesn't have the tiger in it.
4. Why on earth would the immediate power to "heal the world, stop pain, misery, death, disease, despair and anything else you can think of that is horrible - this box will create a perfect world" be a GOOD thing? Especially if we are not equipped to understand or live within such a world? (The machines would have to roll us back to green-hued 1999.)
5. I texture and paint the boxes and use them as decorations in my bedroom.