Describe the project you are working on:
Multiple projects.
Describe the problem or limitation you are having in your project:
In my projects I ofthen have to align two nodes (or more) with the same propertys (e.g. aligning multiple nodes to the same position). So what I do: I go and copy the x-coordinate and paste it in the next object. Then I go back and copy the y-coordinate ... paste it ... z-coordinate ... paste it. UUfff!
Another example: I have two Buttons and create three custom_styles for normal, hover and pressed. I would like to quickly share these StyleBoxes with the other button, so what do I do: I save all three StyleBoxes in the file directory and drop them into the Button. UUfff, this takes a lot of time espacially when you want to try sth. out quickly.
Describe the feature / enhancement and how it helps to overcome the problem or limitation:
This is the solution I propose which is inspired by a feature in Blender:
When hovering a value inside the inspector, the user can press CTRL+C so without clicking the value is copied.
Then the user hoveres the property he wants to past in and presses CTRL+V (optionally the user has to press the property to not exidentally drop sth when not focussing on the mouse)
Here is how it works:

And there could be even more: hovering a property and pressing Shift+C could copy the property name or path so the user can insert it directly into his code. (Imagine such long ones as subsurf_scatter_enabled)
Describe how your proposal will work, with code, pseudocode, mockups, and/or diagrams:
If you have more questions on this, please ask :)
If this enhancement will not be used often, can it be worked around with a few lines of script?:
This enhancement will be used often because it increases the workflow dramatically.
Is there a reason why this should be core and not an add-on in the asset library?:
This is a workflow speedup and huge comfortability feature. This should be part of the major engine.
And there could be even more: hovering a property and pressing Shift+C could copy the property name or path so the user can insert it directly into his code. (Imagine such long ones as subsurf_scatter_enabled)
I would use Ctrl + Shift + C for that instead. Shift is rarely used with a key alone as a modifier for an one-time action. See also #655.
Most helpful comment
I would use Ctrl + Shift + C for that instead. Shift is rarely used with a key alone as a modifier for an one-time action. See also #655.