I eventually decided I simply didn't have the time to continue running it myself; the legal risk is also highly significant (I'm in the UK…), and I'm quite happy that part is no longer my problem, and it all seems to have landed on its feet. I still post there sometimes.
It's very different culturally-speaking to other mediums, but there's considerable variation between different chans, and between different boards on a chan (especially with a huge one like 4chan). It's fascinating how much the medium shapes the culture of a discussion environment. 4chan's perception of anonymity is often relevant to the discourse, in that the removal of persistent identity is thought to remove ego (and karma-whoring) from the equation. I don't think the disinhibition of anonymity/psuedonymity is necessarily a negative thing overall; and yes, lots of other, more mainstream sites, even those with "real name" policies, have unwittingly been platforms for just as bad, and worse.
Managing a site with the size, activity, and sheer wildness of 4chan must have been quite a ride. I can't imagine the full scale, but I think I get part of the general picture, and I just don't know how moot handled it. I don't think even moot knows how he handled it! That part I get. One person can only do so much, and I appreciate his efforts.