I'll try to answer. You can find more accurate answers online.
1) Yes.
2) The data is stored and verified on many nodes. No one can change anything in past blocks.
4) The data stored includes the balance of each account.
Lets talk about an interesting point. Blockchain solves an inherent problem of digital cash systems, called double spending (
https://en.wikipedia.org/wiki/Doubl... prevent,in offline systems, secret splitting.).
It allows person A to directly transfer funds to person B, without having a point where both persons "hold" the same fund and without a centralized third party (see the Wikipedia article).
5) Yes.
6) Blockchain provides a decentralized trusted database. No single entity controls it and all entities trust it. This is a big thing.
7) Web3X library provides access to Ethereum and other similar blockchains features. There are all kinds of features. Not just transactions.
8) a. The blockchain doesn't host your web app. It is only part of the solution.
b. Every action that involves writing to the chain costs ether. This is the gas component. These funds go to the miners.
9) DAO - The ingenuity of the ETH blockchain is that it doesn't just store data. It also has the ability to run code on the blockchain. The code is written in a programming language name Solidity and is executed in the EVM. It is called smart contracts. Once a contract is deployed it can never be changed.
This means that we can build a contract with the organization rules and deploy it. From that point no one can modify the rules, so the organization is decentralized.
10) You have $10 in your pocket and I have $10 in my pocket. These "tokens" are equivalent. You have a car (I'm guessing) and I have a car. These cars are not identical. Each car is unique.
We can track car ownership on the blockchain and each car will have its own specific id. Each car is a non fungible token (NFT).
11) Yes.