Personally, if you can wing it, I think 3 days (as in Monday, Wednesday, Friday) is better - your boobs will be away from her less and you have time to recover in between.

Don't worry if you don't feel full!! I never did and BF till 9 months when I got pg with Little One. I had no supply problems while BF at all.

I am pretty sure you can freeze for up to 3 months, but check in the BF forum or with the ABA.

I would start expressing now, partly to get a feel for how much you express and partly to stock up. You might be surprised how different expressing is to BF, and if Claire is still only 2mo your milk supply is still probably settling down so you might find it easier of you start now than if you wait a while.

believe me, the stress of potentially not having enough EBM for your baby is a big one when you start work and whatever you can do to have LOTS hanging around is a good thing.