I guess there are two separate issues here - dealing with trolling and preventing it from occurring. The mods here seem to me to do a very good job of dealing with it when it arises, and if there is more that mortal members can do then please let us know. Anything that prevents it happening will also impact on upright members of the community more than it impacts on trolls - if for no other reason than that trolls don't stay around for long.
I don't know what kind of interventions the mods need to make to deal with trolling or how much work it involves them in, but is it that big of an issue that we need to start placing restrictions on access or time delays. Though I do like GeoffC's idea of paying subs - then we could have a few bottles of something nice every now and again
