I know that Michael Michele wasn't the best actress, but I always felt that it was messed up how her character was just written as simply Peter Benton's (black) girlfriend and nothing really else. I know she got that one storyline with the drunk kid during the first half of season 6, but they gave her nothing as far as an individual storyline for herself after she got together with Benton. I felt like there was a missed opportunity in season 7 when she seemed like she had an attitude with Carter not long after he came back from rehab. At the end of the episode, he asks Cleo if she has a problem with him being there which she denies and that's the end of it. It would have been nice to have a story where she's skeptical about him as a doctor after his addiction before she eventually trusts him.
They could have done more with Malucci. After season 6, it's like the writers got lazy and turned him into a one note goofball. I'm not saying he had to be totally serious but at least give him more moments like he had with the incest victim in season 6. In the end, they can have him quit like Chen did temporarily after Weaver made her give up the Chief Resident job after that patient died. Anything is better than the way he got fired.