(1) Ernie imagines being at the park in the night. He imagines about a man buying ice cream, a barking dog running through the leaves, a walking horse, and a loud radio. After that, Bert yells "QUIET!" and says that there's no man buying ice cream, radio, dog, horse, and running through the leaves. During the end, Ernie imagines hooting owls, meowing cats, trumpeting elephants, and vacuum cleaners.
(2) Bert and Ernie's bedroom.
(3) I kinda liked it.
(4) The same ending music from "Ernie's pizza & grape juice".