The key is pacing yourself. Set goals and take a pause to do something else. Right now I'm working on all my crafters and during the ixali beast tribe (1-50) I took a few days off from it here and there. It's took longer as a result yes, but I avoided burning out.

As for combat classes, there are other options than Palace. Daily beast tribes give good experiance and you can do some dungeon roulettes as well. Getting to 50 can be fairly easy.