I think a tutorial shouldn't be mandatory, but messages should really recommend a new player to go through it before going in game, just like in many games I know. I don't like the idea of forcing everybody to pass through a "roleplay tutorial", unless it is completely seamless in relation to the rest of game and looks like a natural part of it on its composition.
I mean something like a NPC talking to you just as you arrive who you can ask questions to(Perhaps using a system like Oblivion's - choose subject you want to ask about, then type the IC message of your character - ,because a significant change on the way NPC chat currently works is also very important for user-friendliness, as really effective chat AIs are very far from ou reality), and then this NPC will recommend him to talk with another NPC. While that OOC messages would them appear explaining detailedly the controls and such, among pieces of roleplaying related with the occasion where your character is(also a good moment to teach /me and /my), perhaps a quest could involve going into the pub, and then the NPC said you could ask for a beer and he would pay for it. Then a menu would explain to you to think whether your character does not drink alcohol or not, and give the appropriate answer like "Sorry, I do not drink", or "No, but thanks for the offer", as an example of a roleplaying tutorial in context with what is happening. I know it is no easy deal, but this is definitively something to look for, but I think this is more of a case for the wishlist, perhaps.
With a tutorial and clear warnings in-game about the roleplaying nature of Planeshift, also there will be no excuse for the noob who insists on using LOLZ, ROFL, WTF and such on main chat and without brackets. Perhaps a smaller part of the tutorial on its ending about godmodding and how to avoid doing it could also be implemented, to make things even more clear.
And lastly, closing the gaps around the Settings will really contribute indirectly to improve the overall quality of roleplay, because then the grey area will become smaller and smaller, making things much easier for those wishing to involve their characters in those and difficult for those who intentionally exploit these areas to conceal godmodding.