A better analogy would be the founders of TPB. They went to jail for getting money from pirated content (ads). What do you think will happen to you when you try to extract any money at all from a network that people are using for darknet purposes? And you're adding Tor support and testing Tails for them.
Except wait, you're insulated from these ill effects because your founders are former spooks. You have ties to protect you.
I wonder why anyone would want to create a Tor equivalent for a marketplace for physical goods? Especially the government?
It's interesting how you're deflecting at the end -- I do think this is a terrible idea, and has the potential to unlock the gates of hell onto the world in the form of addicts having an endless supply of their addiction at the push of a button. But if you're determined to build your business on the backs of these people, then I am determined to beat you. If this technology is inevitable, then I think it's best not to let you come out on top. We'll see if anyone agrees.