Thanks chaley for the info, that is nice to know about the pasting series name only. Would never have figured that out without you mentioning it - my "guess" would have been that it would have given it the next numbered sequence for that new series name but that sounds much better.
The other reason not mentioned that I did not automatically post the plugin was that some of my perceived limitations in existing functionality in the tag viewer/bulk metadata dialog will perhaps disappear over time. For instance I think it would be fairly easy to change the tag viewer code so that instead of clearing the search after making a change it researches and retains selections (as my plugin and the bulk metadata dialog does). It should also scroll to make your last selection clicked on visible within the tag viewer itself - try working your way down say the tag list of authors or series to do multiple renames and you will see how much extra effort in scrolling, clicking and hunting is currently required.
I know it is probably way too late for this but it would have been nice if the set_series_name function did not require square brackets around the series index, and just took the last digits (\s+\d+) as the series index. So I could type "Doom 1" rather than "Doom [1]". If that is too controversial even automatically adding a closing ] bracket would improve things, that way you could hit backspace from the end of the line, change the number and hit enter. Right now if you accidentally leave out a bracket you end up with a mess that becomes the series name with a series index of 1.
Like the search/replace changes too btw, sounds very powerful.