I've extensively tested KD + UW and KD + CQ and I've found that KD and UW cannot activate together, even if they don't share the same cooldown. Whilst one is active, the other one cannot proc. While the CQ gives less power in general, the number of times it procs is much higher.
A guildie OP healer confirmed to me (we in mumble). KD SA and his UW SA procced twice/together while spamming hots. I wish i had KD SA (i only have UW SA and UW BA) so i can not test it myself for Snipers.
What i can confirm is t hat UW SA and PvP Conq SA is proccing at the same time again (i think they removed this sometime ago right?). I see two 6 second Power buffs on my buff bar when i sit in cover with the self-heal talent.
I can post screenies if needed.