Things fall apart #2

As I'm getting  closer to the end of this novel certain questions tend to come across my mind. For   example whether or not Ekewfi and Okonkwo are actually married. The novel states that she was married to another man since Okonkwo was too poor to marry, and when he does older she leaves her current husband for Okonkwo. Which makes me wonder if they are properly married, if that were the case then would that mean that Ezinma is a child out of wedlock? That may not be the case here but the thought still wanders about in my mind. Also another thing that seems odd to me is that even though Okonkwo accidentally killed his clansmen was it really necessary for him to be exiled for seven years? I would understand if it was one or two years but seven isn't that too extreme? Who really knows it is there culture after all. Overall I enjoy the novel and hope that the ending won't so disappointing.