What does Miss Maudie Atkinson teach Scout?

Miss Maudie teaches Scout a lot of things. For one, she teaches by example that you don't have to act like a debutante to be considered a fine, upstanding Southern lady. Thanks to Miss Maudie, Scout learns that it's okay for ladies to potter around the garden wearing a straw hat and men's coveralls.
Miss Maudie also teaches Scout that it's a sin to kill a mockingbird. What she means by this is that there are creatures who are put on this earth to do nothing but good. They do us no harm at all, and so it's sinful to do harm to them. Throughout the course of the book, we come across the human equivalent of mockingbirds in the shape of Tom Robinson and Boo Radley, who for different reasons are regarded with fear and suspicion by the people of Maycomb despite the fact that they're completely harmless.
Miss Maudie also teaches Scout the importance of deflating hypocrisy. One day, during tea with Aunt Alexandra's church group, a nasty piece of work by the name of Mrs. Merriweather utters a racial slur against her maid. This comes right after she praises the Reverend Everett for his missionary work among a poor, remote African tribe. So not only is Mrs. Merriweather a racist but a hypocrite to boot. To make matters worse, she makes a none too subtle attack on Atticus for stirring up African-Americans in town by defending Tom Robinson. Mrs. Merriweather's criticism is all the more galling as she's at Atticus's house, enjoying his hospitality. Thankfully, Miss Maudie is on hand to take Mrs. Merriweather down a peg or two:

His food doesn't stick going down, does it?

Why was finding Alaska so important?

The novel Looking for Alaska is centered around a metaphorical search, which shifts throughout the novel. The phrase "looking for Alaska" refers to the search for identity, in many different senses of the definition.
The protagonist, Miles, begins the novel by searching for himself and seeking the "Great Perhaps" missing from his life. His world changes when he meets Alaska, whom he quickly begins falling for. It's clear from the start that Miles doesn't really understand or know Alaska; instead, he merely views her as the solution to all of his problems. In short, Miles views Alaska only in terms of how she can help him, versus seeing the full person she is.
When Alaska dies suddenly in a car crash, Miles and his friends believe there is more to the story. A mystery surrounds her death, and they have questions regarding all of the circumstances. Here, they are "looking for Alaska" in order to uncover secrets of her past to figure out what really happened on that night. These questions remain largely unanswered.
The last meaning of the phrase can be found at the end of the novel when Miles finally realizes he will likely never have answers about Alaska and the mystery of her death. He admits he never fully knew Alaska and that he will have to let go of her in order to move on. In a sense, he stops looking for Alaska, in order to finally find himself.

Why do the Winged Monkeys have to obey the Golden Cap?

About halfway through the story, readers get a very straightforward answer to this question. The Winged Monkeys have to obey the Golden Cap because the cap has a "charm."

This Golden Cap had a charm. Whoever owned it could call three times upon the Winged Monkeys, who would obey any order they were given.

Eventually, Dorothy acquires the Golden Cap, and she learns that there is a charm with the cap. The Queen of the Mice tells Dorothy about the charm, but Dorothy and the reader are still given zero information as to how or why that charm got there in the first place. We have to wait until Dorothy asks the King monkey that exact question.

"Why do you have to obey the charm of the Golden Cap?" she asked.

The King then tells Dorothy that a long time ago, there was a princess and a sorceress named Gayelette. She fell in love with a man named Quelala. One day, the Winged Monkeys decided to play a little joke on Quelala. The Winged Monkeys picked him up and dropped him in a river. Quelala wasn't upset, but Gayelette was furious about the incident. She threatened to tie their wings and drop them in the river. That would have been a death sentence, since the Winged Monkeys can't swim without the aid of their wings. Gayelette eventually handed out a different punishment in the form of the charm and the Golden Cap.

. . . so that Gayelette finally spared them, on condition that the Winged Monkeys should ever after do three times the bidding of the owner of the Golden Cap.

Would Samuel J. Tilden have made a good president?

Samuel Tilden (1814–1886) lost the disputed presidential election of 1876. He won more popular votes than his opponent, but he lost in the Electoral College after a dubious arrangement gave disputed Electoral College votes to his opponent.
Although we cannot know for certain, it is probable that Tilden would have been a competent president. His personality traits were largely positive ones: he was sagacious, honest, efficient, forgiving, and munificent.
Tilden was a sagacious lawyer who was well-paid for his work. He invested his money wisely and became wealthy, though he was never haughty in spite of his great success.
Many of his positive traits were on display during his tenure as party chairman (Democrat) and governor of New York. He fought against the corruption in the Tweed Ring and Canal Ring. His loathing of corruption could have served the nation well had he become president. Tilden had a penchant for organization and he made the Democratic party of New York much more efficient. His success in New York state brought him to the forefront as a presidential candidate in 1876.
Tilden accepted the 1876 loss without becoming bitter. (In this respect, he was not unlike Al Gore after the 2000 election.) Tilden could have rallied his supporters against the unfair outcome, but he feared the potential repercussions for the nation.
Tilden, a wealthy man, was very generous. He left a great deal of money for the establishment of the New York Public Library.

In Treasure Island, what is Pew's most noticeable feature?

Pew's most noticeable feature is his blindness: he lost his eyes in same attack in which Long John Silver lost his leg.
Pew does not have a major role in the novel. After Jim Hawkins and his mother find the dead Bill Bone's sea chest at their inn containing the coins and the treasure map, they hear Pew and his men arrive. In great fear, Jim and his mother flee with the money and the oilskin packet containing the map. However, Jim's mother faints. He leaves her on the river bank to recover while he creeps back toward the inn. There, he witnesses Pew and his men cursing and searching for the treasure. Pew tries to rally the men to chase down whoever took the contents of the chest. He says:

"You have your hands on thousands, you fools, and you hang a leg! You'd be as rich as kings if you could find it, and you know it's here, and you stand there skulking. There wasn't one of you dared face Bill, and I did it—a blind man!"

We can see from this that Pew is daring and unafraid. He also wants money. He flails blindly at his men with his stick before being accidentally trampled to death by revenue officers.

How do I develop a thesis with three arguments on the topic Karl Marx and modern communism?

The topic, "Karl Marx and Communism" is rich with possibilities for argument. You should read some of Marx's writings and some books written about him and about Communism. That will make your task much easier. Here are some suggestions.
A thesis is an idea which you want to test against evidence. It's similar to a hypothesis in the natural and social sciences. Most people formulate a thesis as a question they want to answer or a problem they want to untangle. Ask yourself, "What is it about Karl Marx and Communism I find interesting, challenging or unusual, and how can I explain that?"
Of course, this means reading. Read as much as you have time for. A lot of Marx's economic and philosophical texts are dense and difficult, but they will reward careful study. Start with easy editions, abridged or annotated editions of his most famous works. Capital, Grundrisse, The German Ideology and The Communist Manifesto are all available with helpful notes and commentary. "Collected works" editions will also give you some of his best stuff, like "The Eighteenth Brumaire of Louis Bonaparte" and his letters.
Once you've got a background in Marx, you might also read up on Communism from other authors. Vladimir Lenin wrote a lot about how to make Communism work in the real world. There are great books on The Paris Commune. There are a lot of Twentieth Century authors, from Bertrand Russel to Jurgen Habermas to Mao Tse Tung, who wrote about Communism or tried to implement Marx's ideas and wrote about that.
The more you read, the more thesis statements will suggest themselves. If you're still struggling, think about problematic connections. What did Marx really think of the working classes? You can find the answer to that in the writings of his colleague Friedrich Engels, but then you'd have to connect it to Marx's own writing. Which is the better explanation of economic development, Marx's Labor Theory of Value or David Ricardo's Theory of Comparative Advantage? The answer is "both," but you could explain why. Is Communism possible in only one country, or must it be a global phenomenon to really work? Leon Trotsky struggled with that one.
If you read first and write later, you'll have a much better grasp of your task and the possibilities. You've chosen, or have been given, a massively complicated and potentially great topic. Proceed wisely and you will be richly rewarded. Make good use of the library. Good luck!
https://www.econlib.org/library/Enc/Marxism.html

https://www.forbes.com/sites/steveforbes/2017/11/10/capitalism-versus-communism-whos-winning-the-100-year-war/

https://www.marxists.org/archive/marx/works/index.htm

When they return to earth, how long will they have been gone, according to the three ladies?

Mrs. Whatsit says,

we'll have you back about five minutes before you left, so there'll be time to spare and nobody'll ever need to know you were gone at all.

Mrs. Whatsit tells them this after they have all tessered, or used wrinkles in time, to travel across vast distances of space. They are about to visit with the Happy Medium. The Happy Medium, dressed in purple robes and a mauve turban, will use her crystal ball so that they can see home despite being so far away. Here, in the crystal ball, they will see the Dark Thing (evil) that partially covers the planet Earth. They need to learn about this force, which has been battled by great religious sages, great artists, and humane people over the course of Earth's history, so that they can fight it in Camazotz.
Of course, to us as readers and to the children, they seem to be gone for a long time! The fact that Mrs. Whatsit can get them back to Earth five minutes before they left is truly fantastic.