Maybe... This might be something weird to suggest but..
Paladin: Put levels into improving some melee/defensive skills (while in trans), effecting their core mechanic somewhat and slightly buffing their %s + more passives.
Beast: Put levels into improving most offensive melee skills (and windguard) while in trans. (maybe a passive or two, but not as many)
Falcon: Put levels into improving range skills (maybe a passive or two)
Dark knight: One main passive for each 'roll' with 2 skills for each roll. (No putting points into regular skills)
How does that sound?
Oh, and of course, the option for Humans to go back and forth from pally to giant, once every 15 days.
We don't need to make transes even more different than they already are. We need new skills that all four transes can use. We need more trans skills period, we don't need to divide them up further. If anything, Control of Darkness, Full Swing, and Magic Missile should be changed to be usable by all transes.