I always refer to the switchbar buttons as "window tabs" anyway. Sorry to say I don't understand how anyone can chat in 80 channels.

If your Fileserving in 80 channels, Or doing some other bot like activity, I suggest you run a seperate copy especially for that, And just use a seperate mIRC for actually chatting.

You can't expect mIRC to change it's interface for you bot/drone type people. It's perfectly fine for people like me who chat on a few a channels across multiple networks.