Well... maybe this is a modern-day fantasy where certain sentient undead really are accepted/tolerated as equal citizens, and Tsukiko is accordingly better-adjusted? An Ugly Americans kinda scenario?
The general problem of translating these characters into modern equivalent is certainly there, though. I'd maintain that Miko is actually a virtually perfect fit for a stratified medieval society with objectively real Gods, and just about everybody else in OOTS is some anachronistic aberration by comparison. Whereas allowing orphaned kids to be raised in monasteries is not something that typically happens in modern societies, and senior military/police are usually subject to more rigorous psychological screening.
I'm far from being a gun-wonk myself, so I just gave him what would plausibly be a fairly old-fashioned hunting weapon (I know my dad kept a few shotguns in the closet for this purpose.) But the finer details might be way way off.Oh, all the others I had absolutely no issues with - excellent re-imaginings. About the only thing is that maybe Roy's weapon should be a bit behind the times, to indicate it is a family heirloom - maybe an old six-shooter? But then, for all I know weapons the rifle you gave him is already an old style Winchester, and I just can't tell.
Oops. Right you are. And thanks!