Perhaps Skill Focus could expand the tameable animals to include some vermin or magical beasts.

"It's not balanced" is not the same as "It can't be balanced". As it stands, SF:AE seems to be a wasted feat, as with so many Skill focus feats.

It would be neat to see charisma factor in, as well as Skill Focus.
Druids already have a clear loot distinction between shifters and casters. It would be cool to see the ability for one to become a beastmaster with unusual builds.

@sharkinajar I think there are a few different potion effects that render one immune to a fear aura, which I've seen in the potion shops.