1.) It is called a social contract. You have given up some of your own sovereignty to the government so that it can maintain order. By entering into this contract, you are ensured your civil rights. Social contracts are implicit.
This is much different than a legal contract, and makes very little sense in context of your analogy.
2. Why is point two confusing?
I benefit from public education by having been put through school.
An employer benefits from public education by having been put through public school, and also from having employees (like me) who have been put through school.
It is a problem if he pays proportional to the amount of money that he makes, rather than the amount of utility that he receives from the service. Therefore, his taxes and my taxes should not be the same, because he receives a greater total utility.
This is much different than a legal contract, and makes very little sense in context of your analogy.
2. Why is point two confusing?
I benefit from public education by having been put through school.
An employer benefits from public education by having been put through public school, and also from having employees (like me) who have been put through school.
It is a problem if he pays proportional to the amount of money that he makes, rather than the amount of utility that he receives from the service. Therefore, his taxes and my taxes should not be the same, because he receives a greater total utility.