JCW, first, are you actually John C. Wright or just posting an objection on his behalf? If the latter, I don't think it's quite appropriate to take on his actual name.
This issue was discussed in the comments of Devil's Offers. Yes, you can have a Werewolf contract, and you can have a Jubilee, and you can have various other rules... but some people didn't take on Werewolf contracts out of pride, because e.g. Helion felt it would reduce him to the status of a child. There's also the question of why a decision your earlier self made, should bind all future mind-states forever - could you sign a contract refusing to ever change your mind about libertarianism, say?
Well, if everyone does in fact sign a Werewolf contract and that works - in reality or in fiction - that's fine enough; then you're not living with the everlasting presence of incredible temptations. But the absence of a signed Werewolf contract made these incredible temptations and momentary failures of willpower a key plot point in the Golden Oecumene - a necessary flaw in the Utopia, without which there would have been no plot.
And my own point is that you may just be better off not introducing the poisons to begin with. What people can do to themselves through their own strength is one matter; what they can sell to one another, is another matter; and what superintelligences or agents of a higher order (including a corporation of experienced neurologists selling to a lone eighteen-year-old) can offer in the way of far-outrange temptations is yet another.
So this is Utopia, is it? Well
I beg your pardon, I thought it was Hell.
-- Sir Max Beerholm, verse entitled
In a Copy of More's (or Shaw's or Wells's or Plato's or Anybody's) Utopia
This is a shorter summary of the Fun Theory Sequence with all the background theory left out - just the compressed advice to the would-be author or futurist who wishes to imagine a world where people might actually want to live:
The simultaneous solution of all these design requirements is left as an exercise to the reader. At least for now.
The enumeration in this post of certain Laws shall not be construed to deny or disparage others not mentioned. I didn't happen to write about humor, but it would be a sad world that held no laughter, etcetera.
To anyone seriously interested in trying to write a Eutopian story using these Laws: You must first know how to write. There are many, many books on how to write; you should read at least three; and they will all tell you that a great deal of practice is required. Your practice stories should not be composed anywhere so difficult as Eutopia. That said, my second most important advice for authors is this: Life will never become boringly easy for your characters so long as they can make things difficult for each other.
Finally, this dire warning: Concretely imagining worlds much better than your present-day real life, may suck out your soul like an emotional vacuum cleaner. (See Seduced by Imagination.) Fun Theory is dangerous, use it with caution, you have been warned.