I think the Internet makes a good model for what you're describing. The Internet itself is a good example of a decentralized and (mostly) self-regulated organization. At the highest levels on the behind-the-scenes of the internet are generally boards of trustees/directors (ICANN, ARIN, etc). After that very high level, once you're on the internet-as-you-know-it, much of what you experience falls back on non-authoritarian rules enforcement. For example, it's illegal to send spam email. But most of spam prevention and eradication is actually done by private parties. Ultimately, even when you do regulate the internet with traditional laws, the real enforcement and implementation of such is done by loosely-connected individuals seeking to achieve a common objective. The internet is beautifully self-healing and self-regulating.
I love how you are describing the internet here as far as regulation is concerned. The best way to deal with regulation is self-regulation though there will still be existing laws that can be used in the governance so that erring members of the community can be controlled using those laws. Hopefully, cryptocurrency is going to the route threaded by the internet and that the government will only intervene in extreme cases as can be defined by both sectors.