Trapjaw has always had an enrage, 8 minutes if memory serves. As for the Coruscant world boss one shotting you, he has a "Proximity Laser" that he puts on two targets, the closer those targets get to each other, the more damage they do, up to around 5k per tick. (about half a second per tick) When you are soloing him, he puts it between you and him, and because you are in melee range, you die.