Do you really suppose that state-wide censorship machine is a justifiable and "a very small roadblock" for people contemplating suicide? Are you serious?
Let's put the fact aside that these "instructions" are a joke; consider a wikipedia page http://en.wikipedia.org/wiki/Suicide_methods. Should this page be censored? Since when removing the definition of a word in a dictionary makes a thing disappear? Sure, suicide is an issue, sure, it's better not to have it, but to censor anything mentioning it sounds like a bad adaptation of Orwells' 1984.
What's the problem with suicide prevention, suicide hotlines, destigmatisation of mental health problems? I'll tell you what's the problem - it doesn't help you instill an intellectual control system, censorship and, quite frankly, a form mind control (via media filters).
A censorship by any other reason is still a tool of oppression. It is not a tool for solving problems.
Also, could you please provide a reference to a single study published in a respectable peer-reviewed journal of psychology, which supports your claim that small roadblocks, and especially restriction on amount of paracetamol/acetaminophen sold per transaction helps prevent suicide.
Coincidentally, paracetamol poisoning a retarded way to go - it is probably more painless to kill oneself by drinking a lot of water (6l per 3hrs is enough to kill you). Why aren't drinking water sales not limited then? In fact, why aren't we all absolved of our personal responsibilities and taken care by the state, like some kind of a nanny?