Some ideas ^^

- it would be cool, to add users as friends, and allow only chatting with them.
- block other users, so they can't contanct someone.
- changeing the language in the front-end

I know some chat programs allow users to be added as friends but we may not implement this feature because we believe it is the website that should provide this kind of functionality and not the chat program.
If you look at our chat, you won't find any bells whistles, no share button, no twitter or facebook button(we don't like the mess). we try and make sure the core chatting experience remains pleasant.
but anyone can customize it to add their own buttons though.

- block other users, so they can't contanct someone.
that is a very important feature, we already have an option for the administrator to ban the users, we will soon provide it per user basis.

- changing the language in the front-end
again, this should be implemented in the website, when a user switches his/her language in the website, you can change the code slightly so that the chat loads that particular language file.