you don't have to do boss rush quests to level. high mob density quests are more fun/rewarding and some will net more exp, albeit over a longer stretch of time. my personal favorite for ep1 is tyrell's ego.
Also, TTF spans all 4 bosses, not just dragon.
If you have a decent partisan/sword type weapon, ep4 quest Max Attack 4c, the first room is a good chunk of xp if you know how to back step kill groups of mobs.