Looks quite interesting. I've been thinking about how AGS could be adapted to better handle translations, and my idea was to extract all strings into a resource file that you could view - and edit... but one thing at a time - like this, and have multiple ones for different languages. While this apparently only covers dialogue, it's a great start!
(In my mind there would also be a "comment" field so you could annotate the string with more context information - e.g. VA direction, or notes for the translator - and it would be structured so you could expand and collapse e.g. one particular conversation, or all the lines by one particular character. If your plug-in allows you to sort by any column, that gets you a lot of the way to that second part. I also think that ultimately the strings should be in a standalone resource file, in some sort of text/XML format, so that you could edit it separately from the rest of the game project, and that when you edit the strings in-line in the code, the AGS editor should just pull it from there.)
I feel like there is something like this already, though? Didn't someone post a plug-in or standalone app to handle voice files?