"Do Shut Up" could be a parody of The Young Onesor Bottom, two similarly chaotic British sitcoms that ran on English TV in the early 1980s and early 1990s respectively. They were known for their lowbrow characters who shared a similarly dismal house, and spent much of the show bashing each other over the head with household items.
Micro-asia is most likely modeled after Micronesia.
The scene where Homer is licking bullfrogs on an island refers to the first verse of Pink Floyd's Comfortably Numb song from The Wall album. Marge calling "Hello, is there anybody in there?" over the radio even intones the melody.
Also, a similar storyline was used in Family Guy, where several characters lick frogs and go into a strange hypnotic trance, similar to what happens to Homer in this episode.
There are Hallucinogenic Frogs but none of them will make you Hallucinate just by licking them, it is a more involved process than that.
PBS characters who chase Homer through the streets include The Teletubbies (they fire lasers from their antennas), Oscar the Grouch (who is in his trash can), Elmo (who is sharing Oscar's trash can), Yo-Yo Ma, Mister Rogers, and Big Bird (who comes flying down, squawking angrily like a real bird). The DVD commentary reveals that in order to evade copyright, two of the characters were renamed "Oskar the Grump" and "Elmaux".
As Homer and Lisa Jr. begin to float down the lava flow, he says "Looks like this is the end." At the end of every Underdog cartoon the narrator would say "Looks like this is the end. But don't miss our next Underdog Show!"
The name Micronesia (μικρό νησί) means "small island" in Greek.
On the UK airings, a lot of the rude British slang (like "sodding" and "wanker") are edited.
It is still unknown if Lisa, Jr. survived the ruins of the Chapel being devoured by lava.
When Bart says "wouldn't be the first time" to Rupert Murdoch's "you saved my network" it is true The Simpsons pretty much made the Fox Network.
When Homer tries to hand out Bibles when he arrives on the island, Qtoktok claims that they cannot read. However, when Homer unveils his casino, Ak is able to read the sign. It is possible, though highly unlikely, that Homer taught Ak to read before completing the casino. In addition, illiteracy varies from person to person. Some people are unable to read small text in a book but can read large print on signs.
The craps game is played on a roulette layout, and uses three dice instead of two. It could be Homer's own version of craps.