With this cast there may be hope for this show yet, but for now, make sure your "stupid decision shots" consist of root beer
Updated: For Season 2, this has really gone into "spite" or "hate watching". Reviewers have pointed out that it feels like the writers haven't even watched the previous episodes. Also, the type of gallows the town constructed, a drop gallows, is the kind that breaks one's neck once triggered, not the kind that strangles that someone can be saved from mid-hanging. There are good moments, but they are becoming fewer and fewer.
Start of Season 3: There's an extra complication this season where the majority of characters may be mind-controlled from time to time. So even more blame to the writers when they establish, for example, that the mind controller is losing power faster and faster, and then inexplicably and conveniently controls everyone again. Still more trusting the wrong people and not trusting the right people.
(Descriptions as of July 2015) This is a "worst list."
50s (?) Smarmy used car dealer, corrupt (and only remaining) town councilman, apparent meth drug lord
Mistakes (Season 1) include: A ten-mile wide continual crime spree that he figures no one will solve; believes he's completely wiped out evidence of his crimes when it's later revealed he overlooked insanely obvious possiblities, Making zero leadership decisions such as fuel rationing, buddy system transit, predicting any possibility looting of pharmacies and food stores, using the radio station on a regular basis to keep the peace, or to keep in mind that his ability to remain the town crime lord depends on a semblance of order; alienating virtually everyone including Dale Barbie, the former military operative who appeared to be the last person who trusted him; and worst, letting his son see his hatred for him though he knows his son to be mentally unstable and violent, but, at the same time, letting that son be deputized and go around town armed with a rifle.
Saving graces: Not really any, but earns very minor points for telling people to stop driving after the dome came down so as not to smash into it.
As a villain, he could be consumed with a me-first, only-me mentality, but viewers have no idea where that would have come from.
End of season 2 update: What's changed? At the very beginning, he alienated Junior by telling him to "drink his milk." At the end of season 2, he claims all he cares about his saving his family which is odd considering how abusive he's been to Junior. And then he taunts Junior, who is holding a gun, by calling him a "little boy."
So nothing has changed.
Season 3: Doesn't trust Christine, so good for him, but it's surprising that he hasn't questioned how she got under the dome. This is odd for him (and Julia) as they were the only two not to experience the alternate reality. His feelings about Junior are a 180 from his behavior in the first two seasons. They come across as jarringly false but are what the writers needed in an attempt to change Big Jim from the Big Bad to anti-hero.
According to the Villains Wikia - Big Jim committed about 13 murders over three seasons.
see more on James "Big Jim" Rennie
New Character Season 2 - high school science teacher with explanations for everything.
Best question viewers have asked so far is "where the hell were you first season?" (In the world of Chester's Mill, it hast been two weeks. And she apparently decided to wait until now to show up - awful considering they establish she has considerable medical skill.
Among her medical skills, is creating a serum that distributes swine flu, but has no knowledge of the virus' strength and never saying, "by the way, pig farmer, you should isolate any sick pigs from the others. I would make a bigger deal about how important it is to secure precious food resources like pigs, but I'm too busy figuring out how to save the town with a slightly deadly virus."
Saving graces: Not much yet. She likely has thwarted some disasters with her know-how, but her arrogance/unwillingness to listen cancels that out.
Update: After clearly acknowledging there are things that don't make scientific sense about the dome--something spiritual in nature---she forgets that and goes back to being arrogant/superior/antagonistic only to be shown up again. She also had a bad habit of trusting/thanking Big Jim which made no sense. Still, overall, after her initial insane plan, she was mostly a positive and caring character.
College-aged son (20-21?) of slimy Big Jim, shows signs of psychosis/paranoia, established that mental illness may run in his family line on his mother's side.
Mistakes: Difficult to know, especially if his erratic, violent, and generally illogical behavior can be explained with illness and, likely, the psyche of a victim of child abuse.
Saving graces: Perhaps not really any, but his monstrous exterior has been peeled back some to show the roots of his pain.
Update: End of Season 2 -- More than anyone else he knows how dangerous Big Jim, Sam Verdreaux, and Lyle Chumley are and then he kept doing nothing about it. He seemed more mentally stable this season, which made him a more likable character, but it's also unrealistic when he's around the person who murdered the love of his life on a regular basis.
Season 3: More so than for other characters, the alternate reality (or "year that wasn't") has been destabilizing for Junior. Kind of like season 1 where his mental illness could explain his irrational behavior, his wildly swinging loyalties are what the writers need, but they make more sense for him than anyone else.By the end of the season, his willingness to kill children shows he's completely lost it.
see more on Junior Rennie
Stereotypical "cool cat"/radio station rock DJ (38?)
Mistake: Town is obviously in crisis, but has no plan to do anything except play music. Is mildly disagreeable with Julia Shumway when she wants to use the station to disseminate information. Somehow thinks that having a captive audience will be a good thing.
Season 2 - The mild-mannered, let's-relax DJ is now the town Authority-Abusing Cop. Not necessarily the character's stupidity, but definitely the authors'. He also tells Big Jim in a voice of a kid needing approval from Granddad, "I got those vandals defacing the bridge." Because...that's what we need to worry about when there are dire shortages, plagues, and murderers. Graffiti.Saving graces: At first, seemed friendly, had a gentle view of continuous non-stop music as a way to make things feel normal which was more believable than the fact that the townspeople as a whole didn't say "what are you thinking, we need to know what's going on" especially since people continue to die after day one ("Dome Day"). So wasn't a character problem as much as general writer error.