Does anyone know if law enforcement will look down on me for using a silencer in the act of self defense? Will it hurt my cause?
Does anyone "know"? No, but opinions are free...
Here's mine.. There's more variables to consider before deciding on a can for HD. As mentioned, beef up doors/locks, make yourself a harder target with a security system/cameras/lighting/etc.. In other words, don't invite the gun fight, prevent it.
Next, are you in a NFA friendly area? Of course, it might be legal to own, but the DA or CLEO might not like them. I suppose that could bring you into more scrutiny, but heavy on the " suppose ".
As far as the "cost of the can and tax stamp " and being confiscated goes after a HD shooting goes, well, what does that really matter in the grand scheme? Unless your HD rig is a NFA MG, rare antique or priceless family heirloom, it would be a drop in the bucket compared to everything else in that situation. Besides that, you can find deals now and then. So, IMO, it takes a while before cost is a real factor.
Now, all that said... I'm a suppressor owner, and I love using them. So much.... Seriously, they make shooting that much more entertaining for me, but I don't keep them handy just for HD. If I had a suppressed firearm closest to me, and I was forced into a HD situation, you bet your butt that's what I'm using. However, if an unsuppressed weapon was closest to me, you bet your butt I'm using the unsuppressed one. True emergencies don't necessarily have time for putting on armor, ear pro, cans, selecting gear, etc.. I can't imagine having the time to secure ear plugs, let alone a can. So, buying a can strictly for HD is kinda odd to me.. Not out of the question, but just odd.
Also, in spite of my love of cans, the best money I've spent has been on training. Not paper targets at the local range. Training at a training facility with a trainer. I know most people already know all they need and don't have time/money, but I had that same excuse. A friend talked me into going by explaining it like a vacation.. Sort of a "traincation". Best. Money. Spent... Training.
Bottom line, if you want a suppressor, you should have one, but realize that it may not be handy for HD. Training though.. That's always handy, and cheaper than NFA stuff.