Would anyone in the LAMP social circle be genuinely upset if LAMP killed someone for them?
yes, Harley, absolutely. It's a recurring source of tension in Harley and Thomas's marriage
what we've gotta keep in mind is that, while i wouldnt go so far as saying living in Wickhills makes everyone like, a completely amoral bastard, it DOES generally fuck up your sense of scale
ironically, the thing that makes all of their friends and family and just kind of Wince in response to murder is the same thing that makes most of the older generations inherently distrust and Logan
if you live in wickhills, a fae might kill you - you can ward against it, you can plan to avoid it, you can learn all the tricks and rules and sneaky word gymnastics that are known, and one still might just decide they dont like the look of you, and they'll kill you, and there wont be anything you can do about it
to the people of wickhills, this is something like a severe weather storm. floods, lightning, tornados - this is just something that happens. you can plan for it, but you cant stop it. it would be silly and stupid to even try
so they wind up sharply divided on fae as people - you can love them, and accept it. Or you can hate them, and revile it.
Logan is in the position of being fae as a person but having the second stance for himself. he DOES think he should be held to human standards of morality, and the fact that its so hard for him results in a lot of self loathing.
So while most of the Wickhills-native loved ones of LAMP have like a sliding scale, Harley is the only one who is a Hard No. He mostly remains silently disapproving, and mellows to neutral tolerance when Brian is born (it is suddenly a lot easier to shorten the tolerance for hostility when it might be toward your child) but he would still 100% never approve of them killing someone on his own behalf, and makes that explicitly clear to Virgil and Logan.