1) Laws protect us and without them, society would indulge in chaos.
If laws protected us then there wouldn't be chaos now.
2) Capitalism offers more jobs and gives 'everyone' the chance to start a business of their own and profit off it. Besides, it's voluntary. How is that slavery?
Because if your worth is denoted by the amount of capital you have and it's enforced by the government, then it's not voluntary at all. There are few if any autonomous spaces where people can engage without oversight from the government or the economic system. Jobs, are very rarely held in high esteem, and the only time they are held in high esteem is when jobs growth numbers dictate how well a person in authority is doing. Jobs keep people away from their families, place physical strain on bodies and are often what people don't want to be doing. With the exception of workaholics, people tend to value free time over jobs, but feel begrudged to work so that they can provide a "comfortable way of life."
3) Why have such a radical opinion when none of these things are possible? Why not work to change laws and politicians?
Some of these things, if not all, are possible on a basic level. They might not be possible on a national/global level. Also, politicians, if they are good politicians, have to yield to the states/economic desires. Laws themselves are designed to protect the state/social desires. Even if we changed a law, it would still have to be enforced. Enforcement is troubling because it's coercive.
4) We need government to create and maintain roads, hospitals, fire departments, medicine, etc.
A lot of roads aren't maintained by the government
Hospitals: In the age of privatization, many hospitals aren't owned by the government, and prior to capitalism, hospitals were frequently run by churches.
Fire Department: In the town I grew up in, we had a volunteer fire department.
as for Medicine: I know some anarchists oppose the concept of educational institutions, but not all of them do. There would probably continue to be research institutions. Also, a lot of people can't afford the cost of medicine as it is, if capital and government were eliminated, then the value of medicine would change.