When Homer moves forward to strangle Bart, the music from Also sprach Zarathustra by Richard Strauss plays. This music was also famously used at a significant point in the 1968 film 2001: A Space Odyssey.
When this airs on Disney Channel, the Breakdown Train is from Season 1 of Thomas the Tank Engine & Friends.
During the flashback, dramatic music plays while Homer strangles Bart, implying that he's doing it for the first time. However, in "Lisa's First Word" and "The Girl Who Slept Too Little", we clearly see him strangling Bart as a 2-year-old.
A business like Fotohut would have been long out of business by 2009.
When Homer shoot the pizza at the bar, the shotgun's bullet destroyed the pizza, but left the wooden counter intact. A normal shotgun bullet would've left a hole on the wood.