I would like to be able to disable layer groups. For example, right now I have to disable each layer in the "terminals" layer group if I don't want to see any terminals. Perhaps you could introduce an additional check box next to the group title that would disable/enable all sub layers.

Yes, that's exactly what I meant. When playing, I mainly look at my primary screen and only occasionally glance at the map screen. So when I do, I want to have all the developments visible straight away. Its difficult to see whats has changed if you are not constantly looking at the map.

This could be realized via color, or perhaps by adding some timer that counts the time passed since capture, or perhaps some combination of these.

Probably can't be done unless you set up some kind of database or SOE improves their API.