Another issue: it seems that rounded corners and outlines cannot be scaled.

Outline scaling is off by default, can be turned on with the Transformed Stroke option in Document Setup, or individually for objects in Object Options.
Please note that stroke scaling is non-destructive, and it is using the current transform on objects to scale the stroke. If turned off, strokes revert to non-scaled state

About corners: here the default scaling (for some shapes) changes the shape width/height, which will not change the corner (by design, so scaled rectangle corners remain rounded).
This can be changed by scaling rectangles as objects, by disabling the "Direct Shape Transformation" in Settings -> Editing