"But here's my question: why is that nice cover the WSm comes with so @#$#@ tight? Why not have one that slips on easily rather than one that fits like jeans on a teenage girl and is just as much a struggle to get on?"
Hah! or getting them off when I was a frisky teenage boy.....maybe it was because I wasnt near as 'hot' as I thought I was!
Anyway, my WSM stays outside, I turn the mid-section upside down, cover with a heavy garbage bag and then the cover. It takes a little time (especially since I have handles on the mid-section) but I never have issues with water getting in the bottom.