This is what a sling is for. Also training. An AR can easily be fired one handed. Keep in mind just because you're gathering family doesn't mean you have to carry them... (unless they are infants, or very small children) so, pre planing with your family what to do in an emergency. Of course if you're a single parent, and don't have back up... yeah, maybe a hand gun is the way to go.
This would be the incorrect use of the weapon light. See above where I mentioned training. First off, a weapon light (hand gun or long gun) never negates the need for a hand held light. You need both. Always. Secondly, the spill of a weapon light when shined at a floor surface (low ready) should be sufficient to illuminate any room you enter, and identify friend or foe. You need not orient the weapon at any friendly when not needed. If you see that it is indeed a threat, you're there at the low ready. You can engage in a hot second.
In fact, that's the main reason for the light, to avoid the targeting of the wrong persons. The silhouette of a bad guy can easily be engaged in the dark in most cases. However, you need the light to ensure that it is, in fact, a bad guy, and not your son coming home from college for the weekend at 2am unannounced...
Yes, by all means call for back up... However, if you're going to do this, do it before you take off to clear the house. Hand gun or long gun matters not here. You call, put it on speaker, (or ear phones) and pick up your weapon. No hands needed. Better yet, if you have a spouse, they call while you arm yourself and gather the kids. She informs them of what you are doing so they are aware. Once you know they're on scene, you drop your piece.
