To answer you question about cosmic power, nothing changes. You still get +1 def/SpD using it regardless of what offensive stat is higher if I'm correct.Vacuum Wave isn't compatible with Technician. Gen 4 tutor move/gen 5 HA.
I personally would have prefered if boosting moves like Bulk Up and Calm Mind kept the defense they had originally boosted, because otherwise +Attack/+Spdef doesn't exist in-game and it would add some measure of uniqueness without drastically affecting how a lot of mons play. More importantly, however - How does Cosmic Power work?