Nonetheless, and in the final analysis all three parties, seller - buyer - middleman are involved and therefore share in some of the moral and legal implications of their actions. I think this is particularly relevant in regards to this system which from what I've seen doesn't even make as much effort as the pron industry in preventing underage access to, what should be, adults-only products. And even then, there are other concerns about true quantities, dosage and ingredients / adulterants of already potentially fatal narcotics.
As someone passionate about drug legalization and from the apparent level of higher-than-average intelligence I see on this board, it needs to be clearly stated exactly what the ramifications are of engaging in this business model, no matter what your particular role in it may be.
As you and others have pointed out, the Silk Road model does have risks and deficiencies. However, it does offer a great improvement over the traditional, albeit stereotypical, model of buying from shady dealers in crumby places. The Silk Road model even offers improvements with respect to denying access to children. Because the products come through the mail, parents have a better chance of intercepting them and confronting junior on the matter.
I would recommend though that the Silk Road folks add a link at the top of each product category page to the relevant page on Erowid or an equivalent source. Doing so can only help. We can't win this "war" without education.