"Don't they show someone fighting with a zombie underwater in some of the previews?"
I THINK that those were previews for Fear the Walking Dead, which restarts on April 10.
After the slow-roll suckfest that was season 1, season 2 had damned well better start with a bang or I'm done with it.
I know that they wanted to show things as they started, instead of coming in to zombie world as they did in The Walking Dead with Rick coming out of his coma, but holy *expletive deleted*it, they could have compressed the whole "our neighborhood is an armed camp guarded by the Nat Guard" from 3 episodes to 1.
As for floater zombies, that's an interesting observation. You'd think that once someone becomes a Zed that their stomachs would distend from decomposition and, especially more so, if they ate a human or animal. Yet all of the zombies look like they've come out of a spin class at Ghoul's Gym, even in the beginning.