I think the second of the two films will cover a lot of what Gandalf gets up to while he's away from Bilbo, meeting lots of the folk who eventually feature heavily in Lord of the Rings, there's all that "a dark power rising in the wooRAB" which dovetails into LOTR.
I think Freeman is a perfect choice for Bilbo, better than James McEvoy would have been imho.
As for "getting the same performance every time"... well that's what Hollywood considers as acting these days, Tom Cruise, Brad Pitt, Julia Roberts, Geroge Clooney, Tom Hanks, Russell Crowe....I could go on, but all of the biguns do the same thing in EVERY film.
Oh, and I liked him as Arthur Dent, I thought it was a good reworking, but I realise I'm in a minority there..