No, at first I just felt like the writers went out of their way to make the show gritty and wound up overdoing it. I'm in the middle of season 3 though and it's definitely gotten better.
I never got that "trying too hard" vibe from it at all.
As far as character development, I've been watching Joss Whedon's various shows for the last couple months so the writers of the wire are pretty much fucked from the get-go.
I don't get what you mean.