[CentOS] Network Situation

In my personal environment, I've got 7 machines running, with 4 of those 
machines running various flavors of Linux (CentOS 5 x86_64; Fedora 15 
x86_64; Fedora 14 i686).  Based upon some issues with the Fedora 15 x86_64 
machine I'm considering dropping Fedora 15 in favor of CentOS 6.1.  My 
questions are:
On the networking side, has a there been a move to change the ethernet 
names from eth0 to em1?
After install, can I change from NetworkManager to plain network?
On my CentOS 5 machine I'm running VMware Server 2 and would like to move 
to KVM virtualization on the Fedora 15/CentOS 6.1 box.  Is the level of 
KVM comparable between Fedora 15 and CentOS 6?
If I install CentOS 6.0 and sometime later upgrade to CentOS 6.2, will the 
fact that I'm running software raid-1 on the /boot partition cause me 
grief?
Will the fact that I'm running software raid-1 and LVM that was defined 
under Fedora 12 cause me grief?
Are there any caveats moving from Fedora 15 to CentOS 6?

Any advise?

Thanks,
Gene Poole

+ It's impossible for everything to be true. +