Reducing the dragoon combo by two would mean you’d have to adjust the potency and duration of disembowel and chaos thrust. As it currently stands, dragoon has the smoothest rotation, adding unnecessary clunk to it would not help. Dragoon also has pretty solid levelling experience once you realise that from arr through stormblood the number of full thrusts relative to chaos thrusts reduces by one until parity.

I don’t think jumps can be allowed to grant invulnerability and high damage in the current combat system, they’d just be immediately used to cheese mechanics. The closest you’re likely to get to a proper dragoon jump is the pvp limit break. In addition dragoons currently have most of their burst damage split across buffs and ogcds, not every job needs to be the same.

Breath attacks could be fun, but I can’t see how they’d be done without channeling or the animation immediately being overwritten by the next button.