1. The Hacker is powerful, he or she should start hacking and we have the results of the first Admin-check.
2. I've been playing Mafia IRL for more than 20 years (however, with different rules). For playing Mafia you need both logic and psychology and still it's really funny.
3. It's crucial that The Admins must find their sanity as soon as they can and this should be helped by the others as well (if they can) – see later!
The PVP-er could start fighting as he has some suspicion. This role gets powerful as soon as The Admins clear his/her name.
I've already talked about the The Hacker. But, non-voting may turn the Hacker into a prone target for trolling. Perhaps it'd be good if a Regular civilian (or two of them) mimic-ed The Hacker's voting and non-voting pattern – if so, The Trolls couldn't be sure about The Hacker's identity.
The Inactive One seems to be a "living paradox" for me. His or her bad luck is the good luck of The Admins. Since The Inactive is the only one who does NOT get mod-killed after two days of inactivity, as soon as he or she returns his/her identity is cleared. Therefore, The Admins should check anyone who does nothing for 2 days and starts being active next. After this day The Inactive One's task is finished and most probably gets trolled for good (unless The Trolls have a more valuable target).
I don't understand the role of The Addict so I don't have any ideas about it.
The Veteran should be as active on the forum as he/she can. He/she has some chance to avoid lyching and 50% to avoid trolling! As Ungaros wrote, The Veteran could be an adequate leader of the civilians.
It's obvious that everyone should read this forum as many times as it's possible but it's the most important for The Lurker since he or she should "summarize" everything in one post. If The Lurker starts lurking now, his/her role can be easily identified – another help for The Admins. Thus, everyone else should pay attention: post more than once so as to identify The Lurker. On the other hand, The Lurker might "mix the strategy" of lurking and non-lurking and cross his/her finger for The Inactive One's inactivity. A living Lurker is better than a living Inactive because the latter one has no vote advantage.
The Helper must keep in mind that he or she can protect a player only ONCE. The main "targets" should be obviously The Admins, The Hacker and The Lurker or The PVP-er, I think. (It's no use protecting the other two characters, in my opinion.) So, The Helper must construct a hypothesis about the roles as soon as he/she can.
Finally, don't underestimate the role of the Regular civilian! They can turn the tide of the game if The Trolls start to believe that they are Admins or The Hacker/Helper/Veteran and they might troll non-special players instead of specials. In addition, their regular posting can help setting aside The Inactive and The Lurker. Keep in mind: in Mafia it's your TEAM which wins!