Hi, I am interested in getting a relatively early draconic shapeshifting on a medium BAB class,ideally a druid. Apart from the draconic druid - which I am not a huge fan of - I see that Form of the Dragon is a level 6 dragon subdomain spell. Is there any way that a druid can take this domain, perhaps through its parent serpentkind domain? The Dragon Shaman sadly does not get it, maybe because it is an older archetype.
I'm unsure about your question, however druids can learn an alternate form of the dragon which is rather exotic:
Exotic Dragon
PFS or not? If not, Shadow Dragon Aspect works for a 3/4 BAB class with the sorc/wiz list, e.g. medium/archmage spirit, eldritch scoundrel rogue, warlock vigilante, from 10th level.
A shaman can have some druidic feel, and a lore shaman can pick up sorc/wiz spells via the arcane enlightenment hex. You're going to be horribly MAD if you want to use dragon shifting spells to fight with and that hex though.
As always synthesist summoner is an answer if allowed.
You can play a gish arcane caster. You will have low BAB early on but it balances out once you get into eldritch knight. Also you can do this without even losing caster levels(depending on your feat investment)