All your character data ist stored on the server.
This means you can completely uninstall your game and you player is still stored on server side (somewhere on \"laanx.fragnetics.com\" in a database).
No character data is stored locally, this is also used to prevent cheating... because if the data is stored on each users PC some people get \"bad ideas\" and simply change the file locally (e.g. giving more experience points without playing).
So for all MMORGs character data is stored on the server side.
Be sure to save your login-email/password because otherwise you cannot access you character after reinstalling the game.
If you want to delete one of your characters, I think there is currently only one way: ask ingame a GM to do this (the guys with golden/yellow name label).