Interesting that Cumberbatch did the voice of the Necromancer as well.
I recall reading or watching an interview (probably with Cumberbatch) where it was stated they wanted to link the evil forces of the Necromancer and Smaug together with a similar, yet different, voice. I liked the final result.
Why does my Bolg action figure look nothing like the guy in the movie?
Things changed A LOT during production. There is an interesting behind-the-scenes featurette on the Extended Edition Unexpected Jorney DVD, which details the evolution of Azog. The design of the Bolg action figure was actually one of maybe four or five different live-action/non-CG incarnations of Azog. I guess during production that design was re-used as Bolg (hence the action figure), then eventually scrapped in favor of a CG model. The "action figure Bolg" can be seen fighting in the Moria flashback in Unexpected Journey, which is kind of cool.
Personally I like the CG Azog a lot more than some of the original designs. CG Bolg, on the other hand, sucked in comparison to the live-action design.