Forgive my ignorance but did he actually sell drugs or simply create a marketplace for drugs to be sold?
Yes he sold mushrooms at least in the early days of the silk road.
OK. So anyone selling shrooms should pe locked up in prison and given life sentence without parole.

No amount of FBI propaganda is going to hide the fact that Ross Ullbricht was imprisoned for daring to stand up to the big three (bankers, pharma and Mexican drug cartels).
There's no propoganda. He was locked up for being a darknet drug kingpin (amongst other charges) whether you like it or not. Is it propoganda from the bankers and big pharma when gangbangers of petty drug dealers get locked up? No. Break the law go to jail. He knew what he was doing (and I'm not saying he was right or wrong) but to call it propoganda is just conspiracy theory.
However, the article also gives a link to a first-hand account by someone called Winter, who was present during the trial. I have not had a chance to view the video yet though, so I don't know if it gives many more details.
http://www.youtube.com/watch?v=BJMjGLcdtOA&t=48m5sThat's Alex Winter director of Deep Web and Downloaded (and also Bill from Bill and Ted). I haven't seen the interview but am listening now.