Deleting or Swapping Main IP Addresses

What would happen if you deleted the two main IP addresses? Or can you?

Also, how can you swap the two main IPs (eth0 and eth0:0) with two others already active in the system (say, eth0:6 and eth0:7)? What are the potential issues arising therein?

There’s a brief help guide on changing eth0 on CentOS here:
http://www.centos.org/docs/5/html/Deployment_Guide-en-US/s1-networkscripts-interfaces.html

As for changing eth0:0, why would you want to do that? It’s no more or less significant than eth0:6 and 0:7.