Deep Select
The Deep Select tool provides a means to select objects and points that are nested deeper into the object definition. For example, use deep select if you need to modify an object that is part of a group. Deep select will also automatically turn on control points that can be used to alter the shape of an object. When you are done, these points are turned back off. See my screenshot.

By "Text Box" I'm refering to inside the bounding box made by using the "Box Text" tool, not the text box in the data window.
Once text has been pasted inside the bounding box, it can be edited in the Inspector Object Properties -> Data tab. Selecting the text with the "Select Deep" tool will give you two small red squares at the top left and bottom right corners. These squares can be dragged to re-shape the bounding box.