A pretty good episode all round.
That man Ethan was talking to was definatly Zeke, showing the beard and glue proved that. I thing the others are making themselves look hard done by for the reasons incase any of the castaways recognise some of them, and to try and make it less like they are in control of everything. If the Others (I'm referring to Dharma when I say others, because thats who I consider to be the others, not the lost souls in rags) try to relate or at least make it seem like they are just other castaways, it'll make our castaways less eager to look for answers/shelter/boats and a way out.
I'd say the "he" Zeke referred to was mister Hanslo or a character we wont come across until much later.
In terms of the Jin/Eko not telling about the children, and noone caring about Micheal and Walt: As it's Tv, all we are really ever seeing are gaps into the lives that the episode chooses to show us. And as already pointed out, only a few days have probably passed by. They could probably just place between two episodes that an army has been trained, they're still looking for micheal and walt, Eko and Charlie told everyone about their meeting with the monster and Jin/Eko about them seeing the children. Patience is always a virtue in watching these shows.
Oh and I'd also say that the water was drugged in that scene between claire and ethan, and that the drug they were giving the baby, the label looked similar to the one Desmond was taking.