Pirate I discounted out of hand, since I have Pirate Borg that covers that base so well (and which can be used to run OSR adventures, if one was so inclined).
I was always tickled by the Dragon magazine jester back in the day, but I think both barbarian and paladin have more of a role in 99% of Shadowdark games.
The spellcaster choices are all interesting and could be good. I almost want to see what a librarian would look like, as I suspect if Kelsey didn't have some interesting ideas for it, she wouldn't have included it as a choice. Maybe it's kind of a Lovecraftian researcher into forbidden lore?
That said, necromancer and alchemist more immediately scream out for inclusion to me.