Abitility to set rotation center numerically

Hi I am a newby on inkscape but I really would like to help !

From Pablo's idea on anchors-transformation, I think another great addition to the interface would be to display any object rotation center precise coordinates, with the ability to change them numerically as it is for the size / position.
The toolbar might not be the perfect place to display it, since it would not be useful all the time and would take lot space, but having a dialog as the transform one which would display the center coordinates would really be usefull.

Then having the ability to switch from the 9-common anchors to the user define one would definitely be fantastic !
I also have a question regarding the rotation center and pablo's anchors (see transformation-anchors): if the position of the shape change relatively to an anchors when it is selected, why not doing the same from the rotation center (now called "center"). Then the position of an object is shown either relatively of the selected anchor, either relatively to it's center.
I think it would make the position of an object more homogeneous, instead of having the position relatively to the bottom left anchor when using the rotation center ...

I can provide precise specs if needed (UI design and explanations), I just wait for some feedback to ensure the idea is not completely harebrained.