The only skill level difference tends to be preps for shapeshifters. I do not think adding player control over what forms they get will give any sort of skill increase to the class. If we wanted a skill increase to the class I would suggest adding more abilities to each form. But that is my opinion. They are a lot better since the revamp.

EDGE IDEAS:
Just some ideas. The values are probably not balanced.
Really wanted to get some ideas flowing for shapeshifter edges.

These edges would be mostly expensive but gives shape shifters something to spend the rest of their edges on.

Greater Enlivens
Offense
Ferocity of the Tiger-Meowmix - Small + damage, small increase to +dex and +str
Relentlessness of the Jaguar - Small chance to engrage when an opponent flees combat +2 dam, stacks up to 3 times - would have an echo
Bestial Fury-Killing Frenzy- As opponent gets closer to death damage increases. We are talking no change until gushing +2 dam, writhing +4dam, convulsing +8dam. - Values are there as placeholders
Instinct of the Predator-Blood tracker- Better bleeding from Instinct
Unstable Mutation - Focused mutation - less likely to use an element your opponent is immune or resistant to.

Defense
Recovery of the Snake- Snake?!? SSSNNNNAAAAKKKEEE!!!(MGS reference)-Regen MV faster in form.
Shell of the Armadillo-Diamond Shell-Very small that hits the shell leaves their hand ringing-things like bash would need a different echo. Does a small -4hit -4dam maldict
Primal Tenacity- Not sure where to go with this one
Agility of the Mongoose- FlyingMongooseOfDoom- +2 Dex with this greater enliven active
Skin of the Displacer Beast-Displacement Bite-Free main attack when you actually dodge something.

Air
Eyes of the Eagle-The sky is falling-Gives a bonus to damage of that divebomb attack air shifters get sometimes + makes it easier to land.
Spirit of the Thunderhawk-Sounds good already, not sure it needs more
Deftness of the Falcon-Also sounds awesome
Hearing of the Barn Owl-MostLikelyOP- Hears silent attacks in the same area they are in (not when above). Would hear a tigerclaw, thrown dagger, mocho person being struck, but they do not know who it is doing the striking - kinda like when shapeshifters get struck.

Water
Never played a water major so I'm not sure what they even need.

Brutality of the Shark-Maybe the same as beastial fury for offense shifters.
Litheness of the Dolphin-Sounds good.
Hide of the Walrus-Also sounds great.
Gills of the Axolotl-Also sounds awesome.

Water needs a new greater enliven- Land Shark...
Its edge will be "candygram", which is what the shark says before he eats you.