You're locked in the book until 35. Then you can just /sit to mediate.
As far as the design choices from EQ, they were made based off of Advanced Dungeons and Dragons. I don't know enough about AD&D to say this perfectly, but supposedly hybrid type characters were at a leveling disadvantage there. However, that's compounded in EQ.
Not only are they weaker, due to skills capping at a lower level, but they also required more xp to level. Hybrids are at a severe disadvantage over pure casters or pure melee. Granted, they can do a combination of the two, but they don't do either as well as their counterparts, so it becomes a loss overall. Rangers specifically never had a true focus.
They were part druid, part warrior... except a warrior that could only wear chain. What part of this combination = DPS? In Luclin, they were finally given a niche role as ranged melee DPS, but in classic they were pretty shitty. Their weapon skills and defensive skills were low. They were forced to wear chain... and for some reason they could taunt. It's odd. Kind of like Bards, really. They never did know how to balance a bard out. Thott made long posts about how much Verant screwed the pooch by always un-intentionally fucking bards up.
Even SK's, which are an awesome class, are seriously gimped. They have even less damage output than a ranger, and can't tank close to as well as a warrior (for raid content). They're awesome tanks for groups, however, due to their great snap agro.
They don't really begin to come into their own until after Luclin. And even then they have to wait to become really good.
So in closing, why are the weakest characters also given an experience penalty on top of that?