Domination should probably have either a bar or a cooldown but not both because it makes the gap between permadom and not permadom (and slow clicks) too wide. I'd attribute the dominator's lack of value in endgame groups primarily to the lack of challenging content for fully kitted out characters devaluing crowd control, and that may be better addressed by having sufficiently challenging content due to the broader benefits it would bring to the game.
Being able to set multiple abilities to autofire would be an excellent quality of life change for all archetypes though.