1) Radio is vital for example for commanding artillery, if your arty units without radio get out of contact with their commander, they won't fire their support missions.
2) Squad/platoon/company/battallion/regiment/briogade... commander moving along the line, shouting: "Hold the line!", "Make every round count!", "Give those sonova*****es something to think about!", "There are only two kinds of people on this beach: those who are already dead and those who are going to die. Now let's get the hell out of here.", that sort of thing.
3) It means delay before the shells / aircrafts come in. 0 means the shells will land before your next turn, 1.1 means most of barrage would fall before T+2, 2.0 means all of shells will land before T+3...
EDIT: Oh, and I have forgotten my good manners, so at least post facto... Welcome and enjoy your stay!
