These are all really good points. I especially identify with this, though possibly for the opposite reason from you:

- Fit skirts over leggings. Keeping snug over the waist and high hip minimizes shifting during wear.

I fell in love with leggings last winter and haven't gotten over it. But it quickly became clear which dresses and skirts are best for that kind of layering, and which ones were annoying. Because if the fit is too tight, the top layer rides up and I get both shifting and a weird strangle-at-the-waist feeling.