chat on loby

I think that would be very useful a chat in the lobby.

Are you talking about the game lobby, where you host your own game? If so, there is already a chat.
If you are talking about a global chat in the main menu... yes, that would be nice.

There you could manage your friends, see who is online, how many people are online and so forth.

I believe @LavaSnake is currently working on a mod that will do this.