Little Details

I'm working on a story where my MC is a ballet dancer. She's built for powerful elegance rather than delicacy, is 5'11, and nineteen years old. This is a fantasy, and things are going on in her mind that are making her a little unstable. There's a scene where she's outside in the rain, walking around a track (as in, made of cinder). My questions are:

1) Is cinder slippery enough in the rain that she could turn a fouette?
2) Is it possible to turn fouettes in really muddy, slippery grass, keeping in mind that the MC is out of it and emotional and so would not consider the danger of such a thing?

This is my first time posting here, although I've been enjoying browsing. What a cool idea for a community, and so active, too!

Using this photo as a reference (or even Vash's style of coat and similar costumes for the more anime savvy among us), I have a couple questions pertaining to this particular style of coat-

First, it's referred to on the site I found it on as just a "highwayman coat." This doesn't sound like it'd be accurate, but I'm not sure-- what were these styles of jackets called in their period? Dusters? Surely highwaymen weren't the only people who wore them.

Secondly, the high double collar- Is there an actual term for that piece (or for that matter, any kind of thick, high collar that sits up high like that). I'm assuming that whole shoulder mantle + collar piece was removable, but I can't find anything that explains what purpose it served. Am I right in thinking weather?

Basically, anyone who's fashion history savvy, tell me all about that jacket (preferably from the first photo, not the Vash reference).

All I can find are modern "double collared" shirts on google, which is pretty far from what I'm thinking of.