More people are buying FRS/GMRS combo radios (that's what I'm using now) and only channels 1-7 share frequencies, so I'd propose using channel 1 462.5625 or 2 462.5875, which even covers the single-channel FRS units.

It would be very hard to get people to observe a channel plan unless you could broadcast a message on all 38 CTCSS tones to both "break in" to people who have set quiet codes and to get them to stop using an emergency channel.

I think that the idea is good, but will take time to get traction.