I did a lot of exploring and found a few more non-combat quests, and got to level 14. However, I've noticed something about XP for exploring that I haven't seen anywhere... When I was level 13, the 'cap' for exploring XP was 135; no matter where I explored, I never got more than 135 XP for an area. When I hit 14, I started getting 145. I seems the optimal way is to do all new quests available when you get a new level and minimize exploring until you can't do any more quests.
I've done some work on a Draenei hunter, but I've already goofed up and missed a 'referral' quest that I can't get now. Since she's only level 3, I think I'll restart her at some point. There might also be an 'optimal' race that can level up in their starting area enough to make a noticable difference in maximizing exploring XP.