if you have more than 2 hub servers and more than two frontend server you HAVE TO add all those servers name while creating RGC... Or else you would end up with queuing the messages on the HUB server that is not in RGC..
If you still have doubt? setup your own lab with two HUB and frontend server and you will find what I am talking about.
I am not going to argue with you. You only need 1 connector between the 2003 org and the 2010 org.
The source servers are the same as the bridgehead server. If no others are in place then all 2010 servers will sendail to this server to be sent to the 2003 org.
So if i have 2 exchange 2010 I still only need 1 connector in the routing group. what about the memebers, are those created for me automatically or do I have to add them in myself?