I'm not sure if it's different writers or if it was the complexity of the episode that caused some of the issue with episode 5. A lot of work had to go into accounting for player choices over the previous 4 episodes, so that's probably why the episode ended up shorter. Probably things just had to give here and there to make the schedule, including the story.
1. Ben's redeeming moment
Consider that Ben had his moment where he stood up to Kenny. Ben didn't become a hero, but he did grow a bit as a person before he died. Also, if you blame Ben for everything, you can argue he didn't change at all, since Ben managed to guilt Kenny into suicide by zombie. Ben had a hand in one (or two, if you count both Ben and Kenny) more death(s) before he went.
2. Kenny's treatment
Kenny was inconsistent not only with Kenny throughout the series, but with Kenny's speech two minutes before he dies. Killing Kenny in episode 5 was a checklist item, and ... it happened. Not much to be proud of with this writing. Maybe all the effort went into Kenny's death when he saves Christa, which was better. Although I'm kind of surprised Kenny didn't drop a brick on the walkie talkie, which would have put the walkie talkie out of its misery and closed the issue in Kenny's favor.
3. Omid and Christa's fate
It was bad closure, but I feel like Telltale wanted to punt this issue until later, when the writers had some time to decide if they want those characters back. Unless Telltale didn't know whether they were alive, the player should get to know Omid and Christa's status. Maybe Telltale did this as a hook for next season. Instead they could have had Omid show up wearing a new jacket, then mysteriously ask Clem what new shirt she thinks he's wearing. It would have had only slightly less groundwork that it was the hook for the next season.
4. Clem's Parents
Agree that Telltale built up Clem's parents and dropped the potential, deflating the tension without payoff, just like with the stranger. Maybe Telltale can revisit this. Give Clem some nightmares about her parents and that she left them shambling around. She could explain that she was in shock from her kidnapping and distress at Lee's condition ... or that she really doesn't care about walkers. Just another day for her, no matter who they are.