If I could either Marquee or Shift-Click multiple points, right-click and “Edit” them, I could change the line type and color for all at once instead of one at a time!
Yes, you can select multiple object, but only for moving. You can’t edit multiple objects at once. We don’t have plans to support this feature. For example Inkscape also doesn’t support this.
The main reason is complex nature of objects.
Don’t all objects have style? In other words color and line type?
Not all. And very hard to make multi object editing.