All I show in my first post is absolutely possible in SketchUp.
There is a script "Get Dimensions" by Jim Foltz
showing correct size for bounds of groups and components.
A script from Fredo6 "Best fitting bounding box for for a single face" (for 2d elements).
Scripts to show size of edges (or lines).
(Single drawing elements can be added to "single element groups" inside scripts to extract size with above mentioned tools too).
I wander why such a tool did not exist if so widely wished.
A tool that collects size info for every drawing element.
(I know it will duplicate some of the Entity info fields, but it is OK if the objective is to collect size information in one place.)
I'm trying to put all above in a single info label, but my knowledge in programing is too poor.
Is there anyone to help with code? ("Help" in my case = someone to write the script)
For now I imagine it as small label on screen updated on selection change - like this:
Label.jpg
Area, volume, names can be added too, but I try to make it as small as possible, so may be as optional rows in the above label.
Next step will be a dialog, and changing size (input) to act as resize/scale (relative to current axis location for components and groups).