Mork reasons that he can sell 20,000 apples at a nickel each to raise $10,000. In fact it would require 200,000 apples to raise that amount.
One of the imaginary people Mork gave an imaginary cigar to was named Chuck. This was likely Robin Williams ad-libbing. However, as Sleazy's character name was Chuck, it could have implied some off-script conversation between Mork and Sleazy where Chuck disclosed his real name to Mork.
That Sleazy was arrested with FBI-marked bills in his possession proves nothing about his kidnapping/baby-selling activities. He could just as easily have received the money from Mork if he had legally sold Mork, say, a car.
Will Porter is credited as Sleazy. But his character's name is given as Chuck Wilson, alias Chuck Martin, alias Charles Henthorne.
(Mork is getting things for the baby without telling Mindy)
Mindy: (finding baby clothes) What's this?
Mork: I dried my clothes in the microwave.
Mork: It's better to be a father for an hour than to be a father never.
When Cora concedes to Mindy, "Mork's no actor," the direct context was to keep him ignorant of his role in an FBI sting. This was also a playful slam on Robin Williams, who at the time was better known for stand-up comedy, and had very little acting experience.