You can always open topics to roleplay in. There you can invent your own after school activity, or just hang out with your friends and have some adventures (: 

It's the job of the HoH and the prefects to help new students understand the site. A new job with that function would make HoH and prefect a bit redundant. Also it would logically not be possible to invent new ghosts since the known Hogwarts ghosts are very likely still there and can be played as NPCs. 

When a name is not allowed it is changed for free by the management of the site, same when it is misspelled (: 

We can see that trolls are a big problem on some sites, but for that we have the troll mode which makes it impossible for trolls (or rather the new users in general) to use the chat, open topics or write on walls etc.
Ban new users from the chat would make it a lot harder for them to figure out how the sites work since they are not able to ask questions and could easily feel left out. So at the moment we consider this idea as not possible, sorry.

To make the experience more uthentic free meals are only available at realistic times (breakfast, lunch, supper) just like in the Harry Potter books. However you can always buy food and drinks in the stores and feed an that when you missed a free meal (: 

A great way to earn money is to correct homework (: For every corrected homework you get 5 galleons (:

Seperating different age groups will make the communication on the side much harder and also excludes certain groups, so this is not possible. Everyone should always write in a polite and friendly way, and just as Kumiko said all conversations should have X rating, unless you know that the person you are talking to is an adult and is okay with stronger language.