Anarchism, as most advocates will point out, doesn't mean 'no laws', it means 'no rulers'.

Most of your questions above are answered very simply, by the fact the the true law always exists, and an anarchist society, like any, would only thrive if the real natural law was observed.

The (basic) common-law, as it's known, would still be the framework of law under anarchism. This is law that was natural to the people - and was written and enacted by them, not by government or by lawyers (until later on).

An anarchist society would still have to have the laws of contract, trust, tort and so on - because these are the laws of morality, and morality is what makes humanity human.

An anarchist society would still have juries to make collective decisions (e.g. infrastructure) because that's the only way to make lawful decisions. It' s all just natural law, and it's very logical and well established.

The only thing such a society would lack is people who claim the right to break the law, under the guise of 'government'.

Anarchism isn't a fringe-belief, it's basic morality and adulthood... It could be better understood though...