A basic terms of service and code of conduct would be appreciated on accounts when registering (agreeing to them for already registered accounts if implimented would be needed for legality purposes of course) that must be agreed to. Adding the code of conduct to the FAQ on top of this would be advisable so that set rules can be referenced.
Not saying that things should be insanely strict, but some level of moderation would be nice. Especially when you keep in mind that minors of all ages are indeed present in the public chats.