When it comes to the stress-relief-by-cuddling thing, I use my cat for that. Then I have to wash my face because I'm allergic to cats. I've tried using Significant Others for the same thing, but that either leads beyond cuddling, or (in the case of my ex-wife anyway) her yelling, "I'M NOT A PILLOW FOR CHRIST'S SAKE!"
I've never resorted to the violent kind of stress relief, but I'll admit I've been tempted.
Maybe plushies are a good idea, but for me a big part of the stress relief is the other creature enjoying it. Plushies couldn't care less.