So you have pretty much the ideal gun for the described task, but you really want a pistol caliber carbine. I get ya brother. Do you have a 9mm pistol? I would lean toward something that would share magazines. If you don't have a 9, a lever .357 to go with your revolver. No sense in denying what you want for a few bucks. Buy once, cry once...
Well, no, unless low power hollow point .223 rounds are easily and cheaply available. I just don't see them, at least not locally.
Again, the problem with my .223 is that it's loud, has a bit much recoil for my wife or daughter, and slugs can over-penetrate and / or ricochet way too far for my situation. Address those things still in a .223 round = problem solved.
To be honest, my .223's present intent is for a much different situation: Longer range self-defense or hunting in the event of societal breakdown. Say, if the New Madrid fault repeats its 1811-1812 unpleasantness. (It'd be better to go "bigger", but immediate problems come 1st.)