I suggest adding additional grips to make modifying dimensions easier. Currently, you have to select the Modify Element command to adjust the dimensions. I suggest adding two grips to eliminate this step. There is one at the midpoint of the dimension to adjust the offset and another on the text insertion point, which would allow you to slide it along the dimension line and pull it off into a leader.
Agree! The grip at the text should be in accordance with the text style justification. I'd personally use "Middle - bottom" as it is the most logical one.
Currently even with Modify Element it's, in my opinion, always difficult to position the text in a good way.