Private messages and hiding personal information capabilities?

We love using YACS, but a couple features added would make it a perfect fit for our site.

Our group is primarily connected via the internet and chat rooms, and we don't want to encourage or have real name information requested or available.  How can we disable these fields, either from being entered (preferred) or being displayed?

Because we are internet based, we would like a private message system that allows for easy communication between members.  Has anyone used another program successfully with YACS?  We invision these PMs as separate from the CMS itself.

Thanks for your help,

Jael