Ralph Macchio as Mark Ratner?

He could have done it, but I like Brian Backer in the role, the only character in the film who is so strongly Jewish in a city which is filled with them.Backer had just appeared in Woody Allen's play "The Floating Light Bulb" and won a Tony for it, and that might be why his character brings Woody Allen-style neurosis and sexual anxiety to this film. Another example of how Fast Times is far more sophisticated than other teenage sex comedies of its era.

Who was going to play Damone? Pat Morita?

An extremely cute girl like JJL being into a kid with Macchio's looks would have been a bit more believable. A guy as ugly as Ratner was in the movie would need some good game to make up for it, and he had zero game.

How did Macchio get in the position to demand a certain salary when he wasn't even a household name?

It wasn't until the following year as Johnny Cade in "The Outsiders" and of course his break out role in 1984 with "The Karate Kid" that put him in the spotlight.

Either way, Brian Backer was pretty good in the role and I think casting Ralph opposite Robert Romanus would have made them look like siblings instead of rivals.

Macchio was a nobody when this movie was shot, how could he have salary demands? That seems bogus.