Hi Andi,
thank you for your answer.
First I have to say, that I'm an old guy from Bavaria and my English is very poor - please excuse that.
I think we keep it simple:
1) An angle should be only shown in 2D view, so we habe always two dimensions.
2) An angle should be only shown, if two vertices/points are selected, or when the points on the same position.
3) The third point - please have a look on the picture.
What do you think about it?
Best
Gerhard