Agreed, a decent multi server connection manager would be great. Whichever way its implemented would be vastly better than having to add the network/servers, then configuring perform, then using a script to do the auto connect. Although im not sure if i like the idea of assining a nick/pass combination to networks/servers. Especially for servers that dont use the normal style services (seems it would be incredibly easy for mirc to perform the wrong command and send your password somewhere it shouldnt go). Personally for auto ident stuff, easiest is to add the command to perform, but perhapse a little more secure method is to use the user list (add the networks nickserv mask as a user, and let it trigger an event that sends the pass when requested)
I believe the idea of better multi network support throughout mirc options was discussed more extensively in a thread of two some time ago as well. It definately feels like a 'missing feature' to many users, especially new users who no doubt have a little trouble figuring it out.
Personally i think most of the 'connect' section in mirc options should be redesigned to work on a per-network basis.