Nah GG would be WAY too OP in PvP and PvE if it was unlimited shots and instead drain. Like you said, the OPness of Celestial Nighthawk would probably see 6 man hunter raids and PvP would be horrendous because you'd probably be able to wipe a full fireteam with half a bar, and then kill another 2 or 3 if you saw them quick enough. Especially with the perk that detonates around a kill, that'd be amazing. I agree on the Titan striker... I don't know why they have not changed it up in PvE or given it something, but it is absolutely irrelevant in PvE and that's a shame really. All classes should have some kind of useful utility perks for PvE to encourage different classes running PvE. Most of the time it's Sunsinger, Defender as a guarantee because nobody wants to run without self res or bubble, and then usually golden gun with CN for the damage.