A line is a correct description. In terms of the relevant basic units, options, that is exactly what it is, a vertical line of options.
Yes, but unfortunately this doesn't seem to be possible from Vista onwards.
But then other programs that you may install later might assume the old name.
You seem to be talking about Libraries now, which is another 'feature' forced upon us in the belief that it will do us good. I forgot those when compiling my list above, so ...
??? How can I get rid of the Libraries from Explorer
... also ...
??? How can I get all users to have the same Network Neighbourhood, and have it display in Explorer?
... and ...
??? How can I force searches of the C: drive always to include the Program Files and System folders?
But to return to the Libraries ...
I'm not sure that you're right about that. The Libraries on my W7 laptop don't show any Shared variants at all, so there doesn't appear to be any need to distinguish them.