I think whips and ribbons sounds most apt, theres room for crossover there and I doubt we'll be getting whips on any DPS class.

I like the idea of dancer being a quick rhythmic pure healer with lots of buffing and debuffing techniques.
They could apply their mitigation via damage down debuffs instead of shields, and their cheap quick heals would substitute for HoTs.
This would akso fit the curtent dynamic quite well, as we'd then have three healing roles, HoT, Shield and Buffer, with AST still being the versatile jack of all trades option.
Could even give AST a third sect that increases spellspeed and mp regen, plus doubles card potencies and/or reduces card cooldowns at the expense of Aspected heals, in order to cement that third healing mode.