While the above posters are correct,I'dt like to add that all the games mandatory content, that is, the main quest, can be done with minimal investment to anything outside of it. The quests reward enough gear to do them (and I believe, once SB is out, the 3.x interim quests will also offer gear to stay up to pace) so there should be no need to get into the "end game gearing" if you don't care about the optional battling content. Also as a crafter to have at least one battle craft class leveled means you can keep up one retainer of the same class, which helps in getting some of the monster drop ingredients. So while you can't totally ignore the battle classes, you can still play very devotedly for crafting and gathering.