Carl,
1. When you are finished with snapping refactoring, don't forget to update the Release Notes. From my viewpoint, what matters is using of Shift for no-snap mode and it working the same in all tools including node edit.
2. The new scaling origin mode you did does not quite work. The "outermost point" mode works, but the "bounding box" mode does not. Turn on box selection cue, zoom in and draw a small rect with thick stroke. Now when I drag the right handle, the left edge of the rect also moves a bit in the same direction. It must stay unmoved in that mode.
3. Better names for the options are: - Opposite bounding box edge - Farthest opposite node [not point]
4. Additionally the bbox option does not sit well with the "scale stroke" option. When I don't want to scale stroke, i.e. use a compensation after scaling, that compensation moves the bbox of the object even farther away from the original position, making the bug in 2. above worse. This mode must check the value of the "scale stroke" option and take it into account.