No, just configure a virtual host on www.whatever.com to do a redirect to whatever.com
Just configure a normal Apache virtual host, except have it redirect all traffic.
Your member script "kinda messes up" - can you be more specific?
The chances are you're setting cookies in a daft / strange way which doesn't work with some URL schemes. This may be fixed by URL canonicalisation (Google URL canonicalization for more info (note American spelling)).
URL canonicalisation is generally a Good Idea.
Mark