For this discussion, let's disregard law.
From a moral standpoint, Ross is not innocent. He attempted (unsuccessfully) to murder a potential rat; on the other hand, he's most likely saved lives through opening the Silk Road. Not only have lives been saved due to the lack of a physical aspect in drug exchanges online, but because he genuinely encourage responsible use.
He also attempted to hire a doctor to give medical advice to those on SR seeking it. As you can see, I'm somewhat biased. He did (or attempted) some fucked up shit, but he also produced a lot of good. I think that that good may counterbalance some of the shittiness of the attempted murder thing. I can't think of an exact number of years in prison he deserves to serve, but I do think the 30 year minimum seems morally unjust.
Thoughts?
He's not a threat to society, and I highly doubt he would do the same thing again. However he is a smart guy, and was aware of the possible consequences of his actions. Whatever sentence he gets, he does not deserve life in prison.