The half-elf starpack warlock in our group also has relatively low AC, but at the end of the day, she manages to be one of the few left with healing surges.
Dire Radiance, does a good job of keeping one enemy away from her. And Ethereal stride can get her out of a jam when needed. She also moves around a lot to gain concealment and to position herself in less dangerous places. As long as the rest of the party are doing their jobs, she hardly ever needs healing. She has gone down a few times in combat, but such is the life of a striker. Defenders get the priority healing. As a striker, she is just focusing on hitting better and harder with feats like Improved Fate of the Void, and Astral Fire.