So here are my thoughts on lv. 83 DNC buff damage:
1. Tech Step should add another buff on top of Standard Step either to your partner or the group.
2. Improvisation must add some kind of damage boost to offset the 15s no DPS while charging your ability. It can be either a DPS boost AoE area effect, improve Devilment, or add a different DPS buff all together.
3. Alternatively if you don't add a dps boost to Improvisation then you must at least allow Steps to be used while charging up.
4. Reduce the cooldown of Devilment to either 60s or 90s, 60s preferred to line up with everything else.