The prohibition era shows that you can't legislate against demand. It's not a large blanket covering all legislation. I'm actually in favour of smaller governments than that which is common in the Western world, but not because I believe governments are somehow evil conspiratorial agencies fundamentally concerned with increasing the governments influence... but because government policy is often inept, poorly designed, and only reacts to proximate causes, even if the policy is well intentioned.
The way most bad legislation comes to pass is simply because the more politically vocal, large, or rich groups get their interests crammed into law, without regard to other citizens that don't want it that way. A lot of it is purely reactionary. The media reports that drunk driving kills teens, and public demand surges for arbitrarily conceived anti-drunk driving legislation with little consideration for underlying cause or economic and social impact of the legislation. News report surfaces that some percentage of people are under the poverty line, and people come up with well intentioned but poorly designed legislation like minimum wage.
An effective society ought to be governed by the rule of law, not the tyranny of the majority, and I'm afraid that in an anarchy, it will be the latter. The law would be made up and changed depending on if enough people will support the change, your rule enforcing company would comply if thats what the people wanted. If the majority of people in your community abhorred premarital sex, it wouldn't matter if you thought it harmed nobody, or that it was nobody's business, because you could be persecuted nonetheless. It's not as easy as simply moving to a more liberal community.
Society represents a constant compromise between your interests and the interests of others. You have to accept that other people have different opinions and beliefs and that in many cases these interests will be mutually exclusive to yours, in fact, with scarcity being an ever present factor, this is most certainly the case. I personally believe that people ought to be able to do what they like so long as it doesn't infringe on another person's right to life, liberty, and property, but I know a lot of people who feel that they should be able to impose their own personal morality on others, and they may succeed if the majority share that morality.