If you're worried, you might also want to save and mind-read a bunch of people, and load after you identify the ones who are thinking stuff like "Nice weather today," and only mind-read ones with worthwhile information.
While experience for monsters goes down as you increase in level, experience for completing quests goes up as you increase in level, so the rule of thumb is to kill monsters first, and solve quests after that.
You will want to be level 6 by the time you leave the first part of Broken Valley. I was able to do that, although I now know which ones are worth mind-reading and which ones aren't.
