I have a 9mm PCC rifle that still qualifies as an "AR" in the eyes of the law. It is great for target shooting, though I bought it for home defense since the property at the time was quite large. For indoors, it is basically not going to be useful IMO, so the pistols would be first option. Even at 9mm, the penetration would still be pretty high I feel, less velocity but higher mass. IIRC, in ballistics gel, the 9mm penetrates deeper and stays whole, while 556 has the potential to fragment. I have little use for my rifle now besides target shooting and hate to say that I would not have a problem giving it up either. I do like the AR format due to the extreme flexibility and availability of parts to put to use for almost any application, but really don't see the average consumer needing one, or anything with 30+ rounds for that matter.
For hogs, I would actually think a bolt rifle with a larger and/or higher velocity round would be better and would not come with a 30 rounder. IMO, a solid quality bolt would probably be a little less that a quality AR.