To answer the question of where you should level, my vote would be Western Plaguelands at 50. When I leveled my paladin a year ago, I found that the Western and Eastern Plagueland setup was the most efficient way to level as quick as possible. I also picked that particular area because the questgivers tend to be closer to the actual quest objectives. In other words, I think Felwood is an alright zone to level in, yet I would choose Western Plaguelands if given the choice.