John Carpenter (of all people) was the first choice to direct. He was turned down by the producers as he wanted final cut and a chance to do the score as well. Also, his choice for Santa was Brian Dennehy.
Paul McCartney was originally going to write and perform a theme song, but his record label put the kibosh on that.
This was initially going to be an all-out musical, but the genre's popularity was at a low ebb in The '80s so the producers changed their plans.