Having been in Kunark a while now I wouldn't recommend anyone play a Rogue, a Ranger, or a Paladin. The rest of the cast is fine. Even at level 60 with raid gear and an epic Rogues don't parse all that great, Rangers parse worse, and while Paladins are useful as tanks in Classic they have nothing to do outside of group content in Kunark. If you want to be a melee dps be a Monk and if you want to be a non-warrior tank be a Shadow Knight. On almost every encounter in Kunark the top damage dealers are Shadow Knights and Monks. Both of those classes have good utility in groups content as well and are still plenty great in Classic.
All the healers are fine, all the casters are fine, warriors are fine. Can't hurt yourself picking any of them.