Interesting. That rope came up when I searched for "static rope" on rei.com. That'll teach me to trust them...
Well, I'm not the OP, but I think MY question was answered.
By "scrambling" I mean hitting the occasional terrain somewhere between hiking and mountaineering, as in the "75 Scrambles in Washington" guidebook. Class 3 or maybe low class 4. In other words, situations in which a timid hiking partner might appreciate a top belay. I want nothing to do with a climb that would require real protection or have a real risk of a significant, long fall. Also, I'm not really interested in truly technical canyoneering, but I have noticed that there are a LOT of canyon routes that only require a short rappel or two, and I'd like to access them. (I guess being able to use an ascender would be nice, too.) Despite my ignorance, I have rappelled quite a bit, both single- and double-strand. But I have always used military rappelling ropes, even when rappelling on my own. I've only ever used carabiners and figure-8 descenders as a rappelling device, and I'm quite comfortable with them. And I prefer a Swiss seat to a real rappelling harness. (Because I can easily make one on demand, and a short bit of rope is more multi-use than a harness.)
So, it sounds like an 8mm (or perhaps even smaller) static rope would be adequate, and still generate enough friction for rappelling?
I'll read more. Oddly, I do have a mountaineering book someone gave me as a gift once, as well as the Army mountaineering manual.