Why is there no internet or computer in the basement? Why was one never set up?
Are you referring to the bunker? Because the architect designed the place to be a very well-kept secret, even the Parks didn't know about it. Likely they didn't set up internet or anything so there wasn't a signal that could be traced.
What was Geun-se popping his head out of to peep at Da-song eating his birthday cake?
He was coming up the stairs from the basement.
Getting food obviously. He just didn't expect that Da-song wanted some midnight cake.
Geun-se has been said to be abusing the Morse code lights daily for many years (that means thousands of days). Why was Yeon-kyo only realizing the lights flickering while she ate the Chappaguri?
She isn't just noticing it then; she acknowledges it to Chung-sook and dismisses it as the lights being "buggy." The Park family doesn't notice a pattern to the flickering and since Geun-se mainly turns the lights on for when Mr. Park comes home, they likely assume it's operated by a buggy motion sensor but the disruptions aren't serious enough for them to investigate the lights.
Won't Ki-taek be found eventually if his new "hosts", the German family, realize that food is missing and put up some cameras around the kitchen?
Possibly, but that's irrelevant to the ending of the story.
This is a family, a very wealthy one at that. There's probably a lot of food in the fridge to begin with so if stuff goes missing they most likely wouldn't notice.
The movie implies that the rich Park family were unaware about a lot of things in their own house and household tasks which made them rely almost solely on Moon-gwang for it's upkeep. It is unlikely that the new hosts who are wealthy enough to purchase a mansion in a foreign country and hire a live-in housekeeper would be more keen about these matters than the Parks. And the new housekeeper would look crazy or incompetent at the least if they claimed that the food was mysteriously gone constantly.
There was no way Geun-se could've known Chung-sook is the one who killed his wife Moon-gwang. How come he screams for Chung-sook to show herself when he escapes the bunker?
There's the scene where Moon-gwang tells him that she's the one who kicked her down the stairs while lying down from her concussion. She explicitly tells him to repeat after her, then says Chung-sook's name so he can remember it.
He also may not have even known whether the younger or older Kim woman was Chung-sook; he tries to kill the whole family regardless, with Ki-taek and Ki-jeong attacked first out of convenience. He attacks Chung-sook only when she enters the fray after he attacks her daughter, although he probably would’ve looked for her and her husband next.
Why didn't the Kims do anything with the money they had been earning?
They were likely waiting to have enough money to have a large house of their own.
They all seem like greedy fools who would rather just leech off the Parks for housing and food instead of buying things with their own money.
Housing is very expensive in South Korea due to its high population density. They probably didn't earn enough yet to rent or buy their own.
It looks like they're using the money to eat at the 'restaurant' for truckers, to name a minor example. It also doesn't seem unrealistic to assume the formal clothes Ki-taek is wearing later on in the movie are brand new (although they could just be his old clothes).
Its basically a commentary on why moving up the class hierarchy is so difficult; We don’t ever see them spending the money on anything overtly extravagant or even expensive, and all four of them are being paid, yet their position remains the same.
They do. Throughout the movie, their clothes and the interior of their home are nicer. Jessica also has cash stashed away, so the family was most likely improving their present situation while saving up money to buy a new place-staying in their current home is actually the smarter thing to do, money-wise, as its cheaper than moving to a new place right away.
The time frame of the Kim's infiltration of the Park family depictied in the movie couldn't have been more than a couple of months at best and most likely just a couple of weeks. They probably only got a months payment. And housekeeping and chauffeuring aren't high paying jobs relatively speaking. The son's tutoring job and daughter's art therapy are done under the pretense of informal private tutoring often done by university students as a way to make some spending money. It pays well but it is nowhere near a fully paying career job required to climb the social ladder. This all ties in to one of the themes of the movie, that social mobility is almost impossible, despite all the painstaking(mostly illegal) efforts by the Kims.
Why didn't the Kims try to strike a deal with Moon-gwang once they discovered each other's secrets? The Kims could've promised to look after Geun-sae if she didn't send that video.
They did try to offer Moon-gwang a deal, but once she was in the position of power, she had to lord it over them and gloat. To be fair, the Kims conspired to get her fired and it's understandable she'd take the time to celebrate a victory over the people who ruined her life. But this illustrates the film's themes of class warfare and how the poor are too busy fighting over the scraps that rich people give them to band together.
Moon-gwang's behavior makes no sense to me. Even if she did rat out the Kims for their parasitic behavior, why doesn't it ever occur to her that the Kims would just rat her and Geun-sae out as well as retaliation? And also if she does have money of her own, why not use that to pay off the loan sharks stalking Geun-sae?
It does, in fact, occur to her, and she threatens to let herself go to hell just to make sure they do. She's too enamored with being in a position of power after a lifetime of tiptoeing around to try to strike a deal with the people that just threatened her and caused her to lose her job. And she doesn't have enough money; you are underestimating the sorts of interest rates loan sharks will pull.
Moon-gwang might also be banking on the fact that she's worked for the Parks for much longer than the Kims have, so they have more reason to be lenient with her. The Kims actively manipulate the Parks into firing their old employees, whereas Moon-gwang "only" lied by omission (a very, very big omission, to be sure, but the Parks didn't know about the secret room, and Moon-gwang was buying food for Geun-sae with her own money, not stealing it).
Why does Ki-taek see hiding in the basement for the rest of his life as preferable to going to prison for murder? If he had gone to prison he would have meals everyday, wouldn't have to live in constant fear of being discovered, would be able to see his family, would get to go outside, see the sun and wouldn't suffer from the mental harm that comes from long term isolation.
It's possible he's fearing that he won't get prison for what he did, he'll get the death penalty instead.
He's hoping he can escape someday.
He was also remorseful towards Moon-gwang and Mr. Park, and probably treated this as a penance for his sins.
He was also a rather repressed patriarch whose place in his family was unstable. This possibly made him think that him just hiding in the shadows would save his family of further trouble from a likely more thorough investigation that could implicate his wife for the death of Moon-gwang.
First off, South Korea doesn't have the death penalty. Second off, if he's hoping to escape, he could literally do that any time. If he can sneak out of the basement to get food, he could easily escape out the front door. All he'd have to do is wait a while for the manhunt to die down.
His original escape into the bunker was most likely desperation and panic. Given what he'd done, he needed some place, any place, to hide. The open garage door gave him an easy in to a bunker nobody else knew was there. As for why he stayed there: consider that Geun-Sae was simply hiding from loan sharks and had still been doing so for 4 years. Ki-Taek is guilty of all the crimes his wife and son got convicted of and murder to boot so he has legal trouble to add onto it as well. As horrible as life in the bunker is, he might've considered it the lesser evil compared to what his life in prison would be like and the stain he would've left on his family if the whole case got into the public.
Why did Chung-sook even care enough about Geun-sae living in the bunker that she would call the police? She goes right along with her family's highly illegal and unethical schemes, so she can't have that high a moral standard, and Geun-sae showed no signs of instability when she first sees him. Furthermore, wouldn't getting the police involved be putting herself and her family at risk of getting exposed?
Because she probably considers the Park luxuries to be hers and doesn't want to share. Sort of a 'fuck you, got mine' mentality. 'I've got my escape from poverty, why should I help you get yours'. Just because he doesn't seem unstable now doesn't mean he'll stay stable, given how he's living underground. He (and Moon-gwang) will always be a threat to their cozy lives as long as they're present in the bunker. They can call the police without any trouble to themselves. When Chung-sook suggests it, the situation as it presents itself is just the current housekeeper finding out the old housekeeper snuck her deadbeat husband into her employer's house and stole their food for years. The only reason the other Kim family members get involved and complicate matters is because they fell down the stairs and gave Moon-gwang blackmail material. Had they not been hiding on the bunker stairs, Chung-Sook would've called the police, told her husband and kids to leave, the police would've arrested Geun-Sae and Moon-gwang, Chung-Sook would've been in even better graces with the Parks and everything would've been perfect for them.
(not enough money to set up a savings account). Basically one will struggle whether they save money or spend it on Japanese beer or pizza, so might as well have the pizza and beer.