I just recently finished up the quests in Hellfire Penn too. I followed Suvega's advice and decided to save all quests that were L64 and up, so I decided to do ALL quests, event the collection quests. It actually wasn;t too bad. I was getting about 75k eph. Mind you, I was using 1 priest and 3 mages, so I was able to aoe things about 10 or so at a time. The toughest quest was Cruel's Intentions... I still had to pull in my main for that one....

I do think you'll get to 70 faster by skipping them. But life isn't a race...