Huh, very good find.
I think they should all be synonyms of scripting, which doesn't even exist at the moment. Anyone agree? :)
Hmm. I don't really think of shell-scripting and scripting as the same thing. Shell scripting is a sub-category, but it is a well-known sub-category with a long history and independent existence. "Scripting" by itself is a generic -- it's light programming that might be done with shell syntax/semantics, but it could be done with expect, sed, awk , a little perl, maybe some tcl/tk.
To me, shell-scripting actually makes more sense as a tag, because 'scripting' is so vague as to be nearly meaningless. It's basically a meta tag that means 'a program written in something other than Java or C (or variants)'. Tags might as well be more precise rather than less, and just come out and say 'shell scripting,' or 'python,' or 'perl'.