Yeah, Margaret didn't cheat on her first husband (that we know of), Nucky had him killed in the first episode because he beat Margaret and killed their unborn child. Also, he was German, hence her having the surname Schroeder.
Anyone else get the feeling that Margaret will be drinking some sour milk in the next few weeks? Who would want to bring a child into Nucky's world?
As for Chalky, I joked after the first episode that the only reason he was on the show was that they wanted Omar in the cast, but that joke almost seems to be true. He's sadly underutilised, he rarely plays a part in the big main plot, and often shows up for one scene in an episode to justify being part of the cast. It makes some sense, being a black guy in that era forces him to live in a separate world from the rest of the cast, but it is disappointing.