It would be best to use the "Annotation" Tool for rotating and scaling these text notes, although you should also find that the "Scale" tool would work when you have multiple selected text notes. As the 'geometry' for the text note is very small (effectively a point) scaling a point is problematic. It all comes down to computing the bounding box of the selected elements. The "Annotation" tool will allow you to select a single piece of text (an annotation feature) and you can effectively scale it as well as rotate it and edit the text.
All these tools are available from the Edit tab's Modify Features dock pane as well as the ribbons Tools gallery.
