The minor characters you would keep

[GillesDenver]

The Dynasty producers gave his plot line to Geoffrey Scott as Mark. I wonder if there's any mention of Simon's character in the Season 3 Bible @GillesDenver

No the bible did mention Mark but not Billy (Simon's character).

 

[Monzo]

Gordon Wales could have been slightly more prominent during the series' entire run, well, at least from the moment he shows up.
Not as a big mover & shaker à la Cliff Barnes, but as a recurring supporting character whose actions could complicate situations in a fascinating way.

I recently saw James Sutorius in a rerun of Murder, She Wrote playing the husband of Pamela Bellwood—who, incidentally, was playing a bigamist and was also married to Mel Ferrer in the episode. Although the chemistry between James Sutorius and Pamela Bellwood was rather average on Murder, She Wrote, I still wondered if Gordon could have been a love interest for Claudia at some point—perhaps during her downward spiral in season 6, or in place of Dean in season 5.

 

[Werewillie Oleson]

playing the husband of Pamela Bellwood—who, incidentally, was playing a bigamist

Aha! I remember that episode, but I've forgotten whodunit. Actually I always forget who the killer is but that makes the episodes rewatchable.

 

[Ked]

Aha! I remember that episode, but I've forgotten whodunit. Actually I always forget who the killer is but that makes the episodes rewatchable.

Here's a hilarious episode review of it: