IMO what Barriss needs is a 50% increase in her basic damage.. any higher is too much for a healer. Along with a slight speed increase of about ten points. The speed increase will mean she heals a little more often with her passive hit heal
On top of that, her passive debuff needs to be made into an active debuff ability that grants tenacity up for one turn, or turn meter.
That would in my view make her much more viable a healer and an alternative to Luminara or Old Daka.