Glad you are up and running with it, though I must confess that putting over 2,500 books into the same series isn't quite the standard use case I had in mind!
As for defaulting the series name - that is something I won't change. It is far too useful for people wanting to do quick renaming etc of the series to have the existing name present. The series name is displayed both in the dropdown and in a column next to each and every book - I'm afraid there are no excuses for not seeing what the new name is
