WLAN security question

Hi

Our network is mixed Windows 2000/2003 Servers (both DC's are Windows
2000 though), clients are Windows XP SP2, although we do have
occasional visitors who use laptops with Windows 2000.

We are implementing a wireless network...there is a section of the
office without floor boxes for ports, so instead of running cables
through to them, we'd like to use wireless.

We were thinking of using a Windows 2000 RADIUS server with Certificate
service (enterprise CA) and IAS installed, which we built yesterday.
However, any certificate server should not affect the normal wired
users at all.

We were looking at the help section for configuring automatic
certificate allocation from an enterprise CA, however it states to edit
the Default Domain Policy as such;

Computer Configuration>Windows Settings>Security Settings>Public Key
Polices>Automatic Certificate request settings.

...and create a new Automatic Certificate Request.

My question is, will this affect all users and computers? Or is this
change only applicable for computers that request a certificate to go
to the Cert server. My understanding is that the certificate would be
used between the wireless client and RADIUS server.

Secondly, are there any useful links on how to configure the CA? I've
looked but can't find anything straightforward!

Thirdly, is there anyway to use the RADIUS server to authenticate the
user without involving the certificate server? Or is this unsecure?