This should be a pretty easy one as wikia is under CC and as a result, all content is available for anyone to use, provided they credit the creator. As such, using anyone's code is all above board, so long as you don't try to pass it off as your own. If an incident is reported, edit logs and such can be accessed and action will be taken at the discretion of the staff.
Do this more carefully than you would disarm a bomb. Do not advertise, bar a couple of possible exceptions. PM's in chat, acceptable if a person has requested the link. However, if the person recieving the message is not okay with that, further action will be taken. On your personal page, you can link content you have created if it seems relevant. If, however, you are shameless in the process and it becomes irrelevant, a member of staff will remove the link. Repeated instances may be punished with bans.
Accounts on this site have value, as toward user progression and in particular, number of characters. If people create multiple accounts to get around this, or get around bans, it will be dealt with swiftly, with the ban of one or all of the accounts. If you change your name or have a new account, contact an administrator who will sort out the process of moving everything along.
If a page is vandalised, it will be rolled back and you will be banned. There is no exceptions or reasons. If it is not yours, do not edit it.
General breaking of policy warrants a warning. Three warnings will result in a ban. A warning goes away after six months. If a member of staff feels an issue is more severe, however, it can result in the offending user being banned.