I think Druid should get some kind of "study animal" option to remember new forms ...
For example i would like my Wood Elf to transform into Squirel, instead of Cat.

Yea, that too. I like my cats black instead of white. That's what i mean, the shape you take should fit to the character, at least a bit. Even in there are wildcats in woods, a squirrel would make way more sense to a wood elf.
Same goes for the boar for the dwarf instead of an underdark cow (duergar may be an exeption).
Same goes for your Wood Elf. What reason would there be for a Rothé. An eccentric one who has studied the underdark may come to that but i would like a more traditional approach if i do not have the option to choose.
Choosing from a list would be way better though. That way you can decide for yourself what forms your Druid wants to learn. A stealthy one could forego bearform or somesuch.