What do I need to do a Disaster Recovery of ADFS?
What exclusions should I configure for my ADFS Server?

There’s a really good Wiki article on backing up ADFS on http://social.technet.microsoft.com/wiki/contents/articles/ad-fs-2-0-how-to-back-up-the-federation-service.aspx that is a must-read for any serious deployment of ADFS.

In short; a System State backup that includes all volumes of the ADFS server will be sufficient for ADFS disaster recovery (assuming AD is still present).
A more extended Technet article is also available on http://technet.microsoft.com/en-us/library/cc787348(v=WS.10).aspx.
If SQL is being used rather than WID then a backup of the ADFS configuration database on the target SQL server being used is also required for ADFS recovery.

For Antivirus exclusions for ADFS with WID involved you should combine the exclusion recommendations for SQL and IIS on http://social.technet.microsoft.com/wiki/contents/articles/953.microsoft-anti-virus-exclusion-list.aspx.

For monitoring purposes you can use the ADFS 2.x management pack for SCOM, see http://blogs.msdn.com/b/card/archive/2010/08/06/announcing-active-directory-federation-services-2-0-management-pack-for-microsoft-system-center-operations-manager-2007.aspx for details.

 

Related links:

How to back up the federation service
http://social.technet.microsoft.com/wiki/contents/articles/ad-fs-2-0-how-to-back-up-the-federation-service.aspx 

Back up ADFS components on a federation server, federation server proxy, or Web server
http://technet.microsoft.com/en-us/library/cc787348(v=WS.10).aspx