I've been wondering this for a while now, and it's really only recently started to bug me, but why can't you type numbers or spell the number out when you're chatting?
While developing Wizard101, we realized the style and content of the game would appeal to all ages. As a result of our young audience, we decided to incorporate safeguards that make online play a generally safe and positive experience (especially when dealing with other players).
We have excluded numbers from the chat system to ensure that children who don't know better cannot easily exchange private information.
As for stating your current level, health and mana, the Menu Chat system has these pre-formed statements under the Friendly -> Stats section.
