Fedora Core 2 questions / concerns

[admin at usachurch.com]

Hello,

1.  Where can I find a fairly exhaustive list of differences between 
Core 1 and Core 2 and Core 3?

2.  Is there any difference between Core 1 with all of its packages 
up2date and Core 2?

3.  How is the stability of Core 2 overall?  i have several 
production Core 1 boxes, and they have
performed very well with no stability concerns.

4.  Is it recommended to always do a fresh install, or would 
upgrading to Core 2 work well?

5.  I heard a while back about some completely new security system 
that was being developed into Fedora - something the government was 
involved in as well.  Is there any info you could pass along?

Regards,
Devin