I would suggest that you have created a rather unusual situation. I mention this as I doubt that the prosecuting attorney has handled such a case in the past. Meaning, it would be difficult to prosecute as it is rather novel.
As to what the prosecutor would "come after" you with, he would likely create a paper trail of the transaction that you conducted. While it's hindsight, I would suggest that a prosecution would likely have been completely thwarted by having written contracts giving you explicit permission to conduct these transactions.
As to the computers, it sounds like law enforcement would consider them to have been under your control. As such, you would be deemed responsible for anything on the computers. If there was something unlawful, such as pornography, it is reasonably foreseeable that you might be prosecuted accordingly. Having said that, if other people had easy access to the computers, it would be relatively easy to argue that the items could not be conclusively linked to you.
As to the ability to obtain a "favorable plea", this depends hugely on your criminal history. As you have stated that you have no criminal history, I would suggest that it is quite likely that you would be given an offer of probation with no incarceration.
Please let me know if anything requires clarification.
Also, several customers have asked how they may direct a question to me in particular. If you specifically want me to assist you in your legal matter, just put "FOR JOSEPH" in the subject line and I will gladly pick up the question as soon as I am on-line.