The opening hasn't change very much in the show's run so there are many of the same elements that have existed since 1989. Bart Skateboarding, the chalkboard gag, the couch gag, Lisa playing in the school band, Homer at work, Marge & Maggie in the car among others.
How the West was won
She was never on the show. She did, however, appear in the opening credits.
If you're talking about season 7, he was gone from the credits in the very first episode without him.
He voiced Roger in the season 22 episode "Treehouse of Horror XXI".
There does not appear to be any study of historical writings regarding The Simpsons.
No.
Das Bus
Trilogy of Error.
November 1996.
They appeared on The Simpsons Movie.
1987
Considering no one knows who Banksy is, the Simpsons can't draw him (or her) into an episode.