Oboe, unfortunately there is currently no option available for tower-only radar of any kind. The radar setting in set up that says "Tower Friendly" and "Tower Enemy" actually refers to dot-dar (yeah, it confused me too).
Regarding icons, the current setting is enemy short/friendly long. So, you get friendly icons out at 6,000 yards or so and enemy at around about half that (as I recall; it may be shorter).
For what it's worth, a tower-only option is high on the CM wish list. There are certain types of scenarios/events that really require this (night combat, for instance).
Sabre
CT Team