Question: I never really got the line "it came with a black dude, but he kept getting pulled over". What was so funny?
Answer: It's referring to the innate racial prejudice some people have - an inflatable black guy driving a nice car got pulled over, whereas an inflatable white guy had no problems.
Question: I may have just missed it, but what happened to J's female partner, the lady who worked in the morgue, from the end of the first film?
Answer: There's one line where Zed tells J he can't keep neuralyzing partners. J replies with something like "Hey, L wanted to go back to the morgue." So he zapped her and she is back working as a coroner.
Question: Whatever happened to Johnny Knoxville's two characters, Scrad/Charlie? I don't recall him meeting his demise in any scenes; he simply disappears halfway through the fight at Jeeb's shop and never shows up again.
Answer: The worms tell J that some guy with 2 heads kidnapped Laura, so obviously it was Johnny Knoxville's character. He probably waited for further orders from Serleena after completing this task, but they never came.
Question: I don't get the joke where K pokes his finger inside the alien globe and the little alien guys running away from it screaming, "All is lost." Can anyone tell me the meaning?
Answer: The tiny globe is an entire alien world. His small investigative action threatens to destroy them all.
Question: I never understood the two people on the bikes, you know the people with all the stars. What are they suppose to represent?
Answer: They don't represent anything. Barry Sonnenfeld says in the commentary that he simply likes to use that cycling couple as he thinks that it is a cool visual.
Answer: J probably requested a black "driver", but the point is a comment on DWB stops by police - Driving While Black, the fact that minorities are pulled over far more often statistically than white people.