Q is fine. Provided there is a troll / roleless buff you'll do great damage and be pretty power efficient Unlike Electric / Rage / Light / Atomic to name a few Alter your rotation when needed and you'll still do good (not great damage) till soder or sd comes off cool down.
Been quantum since it released. Not one problem with power in fact I am never out LOL. Gotta be loadout, stat points or both.
Power is a thing now. That't intended with revamp. More power=more damage out. Probably the #1 thing you can do to increase your power (other than the obvious skill point) is level your artifacts/augments. Omegahedron is free and it's the best if you're running low on power. Scrap of the Soul Cloak is next best and it helps build supercharge. Your might augments also give power.