Perhaps this topic deserves a sticky....we get asked this question a lot.
1) If you mark your email address as HIDDEN in your profile, it is HIDDEN to everyone except yourself and the the moderator staff. It will appear italicized in your profile, but rest assured, only admins, mods, and yourself can see it.
2) To ignore IMs: You can go into your profile, click on "Personal Message Options", and put a "*" in the Ignorelist. This will effectively "turn off" all PMs (except for system generated messages), but it will still appear on your screen.