I'd like to see more selectable skills for the classes that don't have them.
Allow dark knights to give up melee to focus more on spells like lose third attack to gain a better magic strike that uses more spells like fireball. Give paladins a choice to choose flails and spears but they lose holy word. Or a focus more on spells to gain but they lose polearms, but their lay hands skill works on themselves.
I'd also like to see bards to be given a selection to make their songs better. For instance, a modification that enhances all songs or that makes them have different effects. Something like making reverberate a change damage types or gives them the ability to refrain all songs at the cost of second attack and the extra attack from brawl.
Selectable skills makes for replayability as far as I'm concerned without losing the base of the class. As well, it makes for more variation in the rock/paper/scissors. It bothers me that there some classes have more banes than others. For instance, want to kill most mages (necros aside)? Roll a thief, monk or ninja because they pretty much control the attrition game most mages could play. It takes cabal skills to overcome the weaknesses. Want to kill a warrior or ranger or druid and it takes specific class/cabal to make their lives equally hard. An example is an ogre warmaster is enhanced by his cabal skills as well as it offsets his weaknesses. Being able to cure mals on tap is powerful for a magic vuln race.
A drow invoker isn't really able to offset his low HP by going Savant unless they pick mysterum, which is lackluster in my opinion for fighting Warmasters.