If the metal glowed, so it stood out so you could see it better, just while picking your starting spot it could definitely help speed up the process. Also a 3 second countdown when the final player has picked would be helpful.
Why not have a resource highlight key? We have F11, i think, for showing the path finding map. What about f10, or some other key,to show the resource map? There must be something in the game for it to know where extractors can be placed.
Do it the otherway around, have them always with an icon/overlay similar to what we had in SupCom, have them on by default and have a key to toggle it on or off. Mike