Although I see somebody else suggesting otherwise, I promise you that you can send/receive iMessages (and SMS messages) via your phone number if you have an iPhone. You do have to select your phone number as your "Default Alias" from the iMessage chat network configuration page, though.
I don't think it's that simple, and it's kinda up to Apple. If you have an iPhone, then yes. But if you have an Android phone, from what I can tell, there's nothing you can do to stop Apple from eventually disregarding the phone number attached to your account and sending everything from your email address. Part of the reason I use an iPhone at the moment is because my entire network uses iMessage and I run an iMessage -> Matrix bridge.
