Stupidity: Why didn't Ben go through the town and the bus at a fast speed instead of going at a snail's crawl? The only time he sped up was to go up the court steps. He could've been through that town in minutes instead of the long drawn out gun battle.
Suggested correction: It was difficult for him to see where he was going, and the faster he went the harder it would be to keep from crashing or see what obstacles were in his path.
Stupidity: Abel sends a video next door showing Chris being sexually assaulted by a stripper at the bachelor party, which would actually get him in a lot of trouble as the video shows him encouraging it. Yet, for some reason, Chris and Lisa don't bother to use this important piece of evidence to make a case against his harassment of them.
Stupidity: They say the airline industry was the perfect way to transmit the virus but how would the plane even fly if there was an infected person. In one scene the plane crashed within a minute of an infected person being on it.
Stupidity: Given Louise's character, it makes no sense at all for her to leave Thelma in charge of the money. She's known Thelma for years, and knows fully well how flaky Thelma is. And Louise is shown as a person who lives by "If you want something right, you've gotta do it yourself". She's responsible, perhaps even uptight, at that point in the movie. So it defies everything about her character that she would let Thelma guard the money - it smells like a device set up just to allow the money to be stolen.
Stupidity: Why would the tow driver go around Deacon's truck in the one-way dead-end parking lot to pick it up from the front? He'd have to back it up on the hook, and Deacon's truck would be in Park, making it impossible. There's a reason tow trucks hook up vehicles by the drive axle ends. (00:08:40)
Stupidity: Considering the movie takes place in the winter of '75, it seems unlikely that the babysitter would arrive in a halter top and barefeet.
Suggested correction: I agree that this is a "stupidity", but think your use of the words "it seems unlikely" allows for the suggested corrections already given. Perhaps replace "it seems unlikely" to "it isn't rational." Even if the daytime temperature was mild for winter, the temperature would probably drop by around 30° overnight.
Suggested correction: Actually, January of 1975 was very mild, much like the winter in the northeast this year, so it would not be impossible for the babysitter to wear unseasonable clothing.
Suggested correction: Ordinarily I would agree with this observation, however, I believe the girls outfit matches her carefree attitude. She did bong hits in the family bathroom, laid on the boys bed seductively and asked him if he French kissed so dressing comfortably to babysit isn't out of context.
Adding to this, almost every babysitter I had growing up went barefoot or at least shoeless. Even this past new years eve, the young lady who came to watch my kids took her shoes off as soon as she came in the house.
It is a common courtesy to remove shoes when entering someone's home to protect the carpeting (or other flooring) from getting soiled by whatever might be on the bottom of shoes after walking outdoors.
Maybe I'm wrong, but after watching this movie last night, it sounded like the girl was wearing flip-flops when she walked across the bathroom to open the door. Would it be rational for her to have worn sandals too?
Considering she was barefoot for most of the night, yes, she may have worn them for comfort.
Stupidity: Angela ran over to her neighbor Mr. Charlie when she heard him come home. Angela was complaining that his son and friends make too much noise, do whatever the want, are bringing property values down, act wild/crazy, draw attention to everybody, and she doesn't want the police coming. These may be legitimate complaints, but the way Angela expressed them would bring down property values! Not only was she yelling in the street, she used "m-f-ing" several times, as well as other select words. (00:02:35 - 00:03:07)
Stupidity: Dr. Horniker (MD, PhD) advised Mr. And Mrs. Lisbon that Cecilia could use a kind of "outlet outside the codification of school" and should "interact with males her own age." The Lisbons did arrange a party for Cecilia, but the boys who were invited (or came) were somewhat older. Cecilia, at age 13, would be in Jr. High School. Tim and Parkie were 16-17. Chase looked a little younger than the other boys, but none of the boys were really "males her own age." Had the boys been 12-13 or even 14 and Cecilia's older sisters not present, Cecilia may have a better experience - and not jumped to her death during the party. (00:07:35)
Stupidity: Amy goes into her darkroom and leaves the lock unlocked from the outside of the door so anyone (in this case Adrian) can easily lock her in. Most people going in that room would take the lock with them or lock the door from the inside to prevent this.
Suggested correction: This is a character decision, and a very common one. The house where I used to live had a garage with the same latch type lock. I would always leave the lock on the latch just like Amy did so as not to misplace it. As for your second point about locking it from the inside, doors with a latch lock like this usually do not have a way to lock it from the inside.
Stupidity: Liv was a graduate psychology student when she met Bill and, after marriage and being physically abused, knew that the leaving Bill put her in a (potentially) very dangerous situation. It is best if the abuser does not know where the victim is "hiding" after separation, but Liv brought along Carol to pick up the kids - and they were going to be staying at Carol's house.
Suggested correction: She brought Carol along as a chaperone/protection when she picked up her kids. She didn't announce to Bill that that would be where she was going to be staying, she only told her kids that when they had already driven away from the house. Bill didn't seem to know who Carol was anyway. Even if he did manage to find out where she went, she could have easily got a restraining order against him.
It is more likely that she brought Carol along for emotional support and to act as a witness. If she were looking for protection, she would have used a police escort. It was implied they were going to be staying at Carol's, but, even if not, Carol's presence offered Bill a hint of where to start looking for Liv, and there should not be any leads. Liv unwittingly put Carol in a potentially dangerous situation - if Bill went to Carol's looking for Liv, and Carol truly did not know where she went, Bill would insist that she did and threaten or do worse if Carol didn't tell him. Remember how Bill drilled all the kids about where Liv went, checked their phones, accused Sam of knowing more, then got them into the car and drove like a maniac? Bill has a temper and propensity toward violence (at least when drinking, which he did everyday). Court orders take time to get, but are not very effective. Numerous women who had restraining orders against abusers ended up six feet under.
Stupidity: It's very idiotic that Michael and Karen kept the same security password, even after being harassed and not feeling comfortable with Pete being around them any longer. There's no way the pyramid password should have been kept the same, with Pete being able to enter their home, plant drugs, and frame Michael. Changing your security password, the same password that the lunatic cop once knew, would be the first thing to do after his psycho behavior starts.
Stupidity: When Will Smith and Gene Hackman are running through the railroad yard. Gene calls Will by his real name, "Will" and not by his character's name "Robert."
Suggested correction: You could be a little bit more specific, but I don't hear him say "Will" at any point during that run.
Stupidity: After John's wife is taken he follows them. Four of them spend a good 5-10 minutes shooting the hood and down the side, he pulls right up next to them and they still shoot down the side. Why didn't they just shoot right inside the windows or or windshield? Should have been very easy since all the windows were down and John had knocked out the windshield. John would have been dead and their troubles over.
Stupidity: Outside the bank, Mike and the first merc are having a shoot out across the parking lot. There is lots of room between them and around them. Yet a random construction worker, with a clear view of this shoot out happening, suddenly decides to take off running into the line of fire between the cops and the robbers and gets shot in the leg. Their was no reason for him to suddenly decide to run between them shooting at each other into the line of fire. (00:44:35)
Stupidity: Dirk squeezed a long stream of lighter fluid onto the pile of Mario's clothes, then saw a necklace, which he removed (and potentially got lighter fluid on his hand while doing so). Instead of tossing a match from a safe (r) distance, Dirk crouched next to the saturated clothes and held a match near the bottom of the pile, risking burning himself. (00:06:40 - 00:07:21)
Stupidity: Gunner [Director and Co-Writer Brock Harris] was given a puppy ("Barnaby") by the nurse (?) who told him he was sorry his "[VA] benefits didn't go through." Gunner could have merely refused to take the puppy but, instead, drove away with it - and later threw it out his truck's window while he was driving. (00:24:42 - 00:25:55)