Why are Sponges and Powder Puffs, of all items, used for defense? Because they absorb the attack!
On the other hand, why would a powder puff be used to absorb things? It's used for putting on makeup (it technically does "absorb" the powder you would then put on your face, but still).
One Let's Player points out that the Megasparkle Goomba can talk clearly even while continually using "shiny" and similar words in his speech when later bosses are driven so mad by the Royal Stickers' power that they can no longer articulate. He muses that one would think the weakest (a plain Goomba compared to the likes of Petey Piranha and Gooper Blooper) would be affected the most. However, all of the Royal Stickers drifted down at the same time, which means that the Goomba had been exposed for a shorter period by the time Mario got to him. The madness affected them all at an equal rate, just that the others had been exposed for longer.
Why are disco-dancing Boos in the Enigmansion? Because disco is dead.
Kersti's name can be rearranged into Sti(c)ker. This makes sense as she sacrifices herself so Mario can use her as a sticker to win against Bowser.
Given Mario's Nice Guy nature, it's not hard to imagine he did rebuild Mizzter Blizzard after the events of the game.
Fridge Horror:
In the harbor, a Toad mentioned how a ship and its crew of Toads hasn't been back for a while now. On the last level of World 3, you see the remains of the ship. With nobody remaining. The only other person you see on the island is Gooper Blooper. Think about it...
