(1) is incorrect which renders (2) through (5) incorrect.

1. Blockchains are kept "authentic" by having identical copies distributed everywhere. Obviously a static, unexpanding copy is less useful than a dynamic one that records new transactions, so the copy holders have to be incentivized in order to keep their copies online and updated.

2. IN BITCOIN There is a reward for the first correct guess to a cryptographic puzzle. Essentially an army of computers are brute-forcing a solution. In order to have a hope in hell of coming in first, you need the clue of the last block. more here. Obviously the odds of guessing correctly are really shitty if you're all alone, which is why people talk about mining "pools." Pool the effort, distribute the wins.

3. The "correct" version of the blockchain is the one with the most agreement. If 30% of bitcoin miners decide they don't like the solution to any given block, there is now a fork with 30% of the miners on it, a fork with 70% of the miners on it, and "bitcoin" is whoever has the majority. Every miner needs the blockchain, the whole blockchain and nothing but the blockchain.

4) The more miners on the chain, the more miners need to vote against something in order to change it. If 30 miners in an 8,000 node network decide 7970 miners have the wrong copy, they are on their own pathetic little chain. If 30 miners in a 45-node network decide 15 miners have the wrong copy, they are still on their own pathetic little chain but they have the mother fork, for whatever it's worth. This formed the basis of the last season of Silicon Valley, incidentally.

5. The cost of calculating the next block increases over time so that early adopters are given an advantage. It's monetary policy at the code level. The difficulty of the hash is a choice, not an effect.

Are those differences adequately explained?