Crichton has the line about the Zelbinion: "Just ask Leonardo DiCaprio. Even the big ones go down." The first time the scene was filmed, Ben Browder ad-libbed 'Bill Clinton''s name in the place of Leonardo DiCaprio. They were forced to shoot it as written because it was uncertain whether such a line would be appropriate.
The Sheyang actually appeared in "Premiere", as background aliens talking to Zhaan on the Commerce Planet. David Kemper thought they looked cool enough to appear in an episode of their own.
Zhaan mentions "Starboard" - most of the series uses the alien word "Hamman" instead and this may be the only exception.