Speaking for myself, I would want the three things you mentioned. One thing though - a modder might not want to have the slaves switch to the enemy side when the controlling unit is destroyed (the concept in the hypothetical mod might be that the slaves are soldiers based in the "controlling" unit, or maybe robotic drones). There should be an option as to what happens to the slaves when the "controlling" unit is destroyed (the default for normal slaves being, of course, to switch to the enemy side). As to how much I want this, for me, this is a "would be nice to have" feature; I would rather have 634 for example.
Speaking for myself, I would want the three things you mentioned. One thing though - a modder might not want to have the slaves switch to the enemy side when the controlling unit is destroyed (the concept in the hypothetical mod might be that the slaves are soldiers based in the "controlling" unit, or maybe robotic drones). There should be an option as to what happens to the slaves when the "controlling" unit is destroyed (the default for normal slaves being, of course, to switch to the enemy side). As to how much I want this, for me, this is a "would be nice to have" feature; I would rather have 634 for example.