yeah that is the concern of those not in a guild :) i would just tax my guildmates' exp when they say they have base exp to waste :D
as for getting job exp, some mobs give proportionally more jobexp then base, try to grind those if you dont feel like wasting, and also dont avoid the chief/swift/elusive/solid mobs if you can take them down, cos they give a potents amount of jobexp for slaying them :) of course if they wreck your butt then just aviod them instead, that is understandable.
but yeah, i guess tweaking the exp table of quest to lean more towards jobexp is something i wouldnt be against,
but the other hand, i dont find it that much of concern either, i mean we have a whole bunch of lvl 80-110 and 90-120 range prontera board hunting missions to go along with the eden board quests, doing all those should be enough for one to reach 3rd class just fine.