Progress is beautiful! I read Colins' guide last night.
And for the remaining answers. I would get the 2.8 24-70.
And the 2.8 (IS Possibly) for the 70-200mm.
I definitely see what you mean with the primes, Every time I got through the drill again, i cant see why having a 24-105 as an all around fail safe would hurt, performance seems good on both ends, and it is one of the least expensive low dispersion lenses. Good to have in the bag, but never "forced" to bring it out. The main negative I can pull from is if I have no flash, I'm going to have to push Iso's a tad, but the 5d and 6d preform well in this aspect...