Unanswered things, plot holes and fun facts after rewatching Every season of Stranger Things (Spoilers)

I want to start this off by saying that Stranger Things is one of my all time favorite tv shows/franchises and this is not me criticizing or hating on the show or it's writing. Part of the appeal of Stranger Things is that it allows the viewer to fill in the blanks and participate in theories to build the overall plot of the show. I decided to give the show a rewatch after season 4. And I found myself analyzing it and getting into details that I haven't quite noticed or thought about before. So I'm not quite sure what to name these questions and statements but here are some of the unanswered/unexplained things I've noticed: Season 1: 1 - How did the demogorgon spawn in random spots around town? Can they creat gates to go back and forth from? How come we haven't seen that feature in any other seasons and how come Vecna didn't use that feature for his benefit? 2 - When Will was stuck in the upside, Joyce actually saw him through her wall in what seems like a "glass like window", how come we've never seen the upside down manifest itself this was again? Also, she can clearly hear Will's voice calling for her through the wall but we find out in later seasons (season 4) that people in the real world can't hear anything from the upside down but anyone in the upside down can hear faint sounds from the real world. 3 - How did Hawkins lab fake Will's body and knew all the little details (moles,birthmarks,etc..) when the double was created after Will's disappearance? Were they spying on him beforehand? Also, how fast was that doll made? By that point he was just announced missing less than few days ago, was the doll ready in storage ready to be thrown in water at any moment? 4 - How come whoever was behind the Will body double scandal never noticed the tear in the doll's chest that Hopper made with a knife when preparing it for burial? 5 - What happened to Will's grave? Is it still out there even after they found out he's alive? 6 - Who's gun did Jonathan steal and how come the owner didn't notice it missing? 7 - We've seen multiple guys go to the junkyard to haunt Mike,El,Lucas and Dustin when they were hiding in the bus. How did Hopper hit the "government employee" who approached the bus without the others noticing? He wasn't even quite about it. 8 - How did they get inside the school to sensory deprive El without anyone interrupting them? How did they gain access to the school gym and equipment? 9 - The government employees and Dr.Brenner were so sure Joyce and Hopper wont bring back will and they'll die in the upside down so they let them go through the gate but how did they make it back with will in their arms when the government were very clearly trying to hide a scandal? Season 2: 1 - General question but where did the hawkins lab kids come from? In season 2, El's mom has files of kids being kidnapped from hospitals when they were just born, are they random kids or did hawkins lab specifically "made them"? Because we've seen EL's mom is a newspaper with Brenner not to mention that she was communicating with her through lights. Was all the kids bred by brenner using 001 DNA? And how did hawkins lab get a hold on henry in the first place? 2 - Dustin tells Steve to bring his bat that has nails on it, how did dustin know about that? Didn't Steve only use that in the Byers home? Dustin wasn't there when that happened 3 - How come when they went down to the "tunnels" they didn't flip upside down? In season 4 you can see all the characters literally "upside down" when they move from a world to another (the bicycle scene for example). 4 - What happened to the demidog Dustin and Steve stored in Joyce's fridge? How do you dispose of such a thing? Season 3: 1 - Considering the Russians were on full alert in the mall and the fair and had few soldiers ready to greet Murray,Jim and Joyce after they left the elevator going down to the base, it's a little weird that they got to knock off all those soldiers and steal their identity without anyone realizing it. And then we find another set of soldiers in front of the elevator saying "we found them this way" in regards to the dead soldiers. like, it's a small base how many people worked there anyway? Wouldn't it be easy to track whoever snuck in? Just ask the officer at the end of the tunnel where did they go (since he spoke to Murray and noticed they were newcomers) 2 - How did the Russians know that the gate has been opened in Hawkins in the first place? 3 - How come all the flayed turned into goo except for billy? Does that confirm he is Vecna? Because as far as we saw in season 4, Vecna controlled the mind flyer and was his own entity. 4 - Did no one question why the hospital was such a mess after the flayed reporters turned into that monster and wrecked everything on sight? Was the recipient not alarmed at all? 5 - Erica said that she lied to her parents and said she's at her friend's place when she was helping Dustin,Steve and Robin but morning came and she still didn't go home, was her parents not concerned at all about her whereabouts? 6 - Did Jim,Joyce and Murray just leave Alexi's body at the fair? Did that not raise any questions or suspicions in Hawkins? 7 - How come dustin had a screwdriver on hand but not a set of batteries for his walkie talkie? Season 4: 1 - How did Henry get his powers? Was it from the spiders he was so fascinated with? 2 - In season 1 Joyce mentions that Jonathan's dream college was NYU since he was 6 years old, how come it wasn't even mentioned in season 4 when they were talking colleges? Did Jonathan give up his dream for his family? 3 - What happened to Dr.Owens? Did they leave him for dead in the desert? 4 - Why was the school counselor wearing a grandpa clock necklace and how come Vecna chose his victims from her files? What's the connection there? 5 - How did Brenner survive the demidog attack in season 1 to reappear in this season? 6 - In volume 2, when Eddie's uncle hanged a missing person poster, it said that Eddie was 17 when in the beginning of the season Eddie said he was held back two years making him at least 19/20 years old so was that intentional or did the writers forget? Fun observations: 1 - Season 1, episode 6: In El's memories, when she's is floating in the water bath and encounter the demogorgan the 2nd time she's been put in sensory deprivation, you can hear clock ticking noises in the background. Of course, in season four we learned that this is Vecna's signature not to mention Henry was the one who was banished in the first gate El opened. In fact, the conversation papa has with El before she goes inside the tank indicates that he was forcing her to make contact with Henry (it's reaching out to you, it wants you, it's calling you). He knew Henry was out for Vengeance but he still sent El to him blindly for the sake of experimenting. 2 - Season 1 episode 6: dustin is scolding Mike for being oblivious to lucas' feeling of jealousy towards Eleven since Mike now has a "better" bestfriend. That oblivious comment still applies to Mike's character in season 4, being completely oblivious to will's feelings of jealousy towards El. Despite the fans being enraged with Mike's season 4 character, he has always been that way. 3 - In season 2, 008 motivates El to summon her power by focusing on things that angers her and irritates her emotionally. We find out in season 4 that it's the same way 001 motivated El and taught her how to strengthen her power. 4 - The 3 months later sequence in the last episode of season 3 features a "cutting edge" footage which talks about how the tragedies that kept happening in Hawkins might be linked to the "rise of satanism" which leads the way to the satanic panic in season 4 that Eddie fell victim to. That's all for now. Feel free to add your own observations and interpretations of the show!