I actively take care of my dwarves and animals and ensure they live long, happy lives, and preserve families whenever possible. They get proper burials whenever possible.
I don't slaughter caravans and only steal from them if I absolutely must have something to survive by or they're being entirely unreasonable (elves, occasionally.) I even let them out through the caverns whenever possible, and try to provide escorts for them when entering.
Invaders, though, are treated like crap and left at the bottom of my dodge-pit trap, usually. Sometimes I let them go free after being caged, and don't pursue sieging forces in retreat.
Sounds about like me. I go through pretty elaborate measures to care for my populace. They're all happy, spitting out babies and generally life is good in my forts. Every family gets a nice room. I always do what I can to keep my military in one piece, and even the civilians are very safe with a curtain wall, and an enclosed pier for fishing where the nasties can't get to them. If someone is unfortunate enough to die, they're promptly buried, and the military have tombs predesignated for their squads.
I've never stolen from a caravan, always give them fair trade, and I do everything I can to protect them on their way in and out of the fort.
I even do everything I can to keep nobles happy.
Invaders can go die in a fire though. You come mess with my peeps, and you get what's coming to you. Sometimes I even send out the crossbows to deal with wounded but retreating enemies. Maybe that's mercy, or maybe that's murder. But you don't come with plans of sacking my fort and get away with it lightly.
Forgotten beasts have their own little special trap in the caverns to kill them, rather than risk my military on them.
It's a boring life, but at least everyone is happy. And when tragedy does strike, it hits home for real.