Overdue, and if I recall correctly, a blow of Mt. Ranier would have far more devastating consequences than that of Mt. St, Helen's.
Actually, the real danger from Mt. Rainier is lahars (volcanic mudslides), not an explosion like Mt. St. Helens. The USGS has online maps showing the paths of past lahars, which could reach as far as Auburn and Tacoma.
I think so.
It's much closer to populated areas, I think.
Being east coast I'm not too conversant or knowledgable about it.
(Only what I've read, and I don't really know how accurate it is.)