Local Harvest Gardening

I'm looking to start a worm bin but wondering if anyone has experience using one outdoors. I live in North Vancouver and we have bear, coyotes, raccoons, rats, skunks, squirrels, you name it. Is it possible to have one that isn't sealed away in a shed?

On a somewhat related topic, what should I do about buttercups? They are everywhere and while I weed them out I also see that they are teaming with life. So great for the soil but not great for planting veggies or fruit trees. Any advice?