Thank you for your interest in FinaleScript and your ideas to enhance the experience for all. I will log your request that scripts be in separate files to allow for easier management and sharing.
Concerning creating scripts in your favorite editor, you can already do that. The FinaleScript.dat file in the components folder of Finale 2004 is the file to edit in a text editor. While I do such a thing for a few reasons from time to time, benefits to a 3rd-party editor such as auto-formatting, error checking and keyword highlighting are not supported because FinaleScript isn't seen by those editors.
As for a public/open-source library, this forum is the beginning of that. If things take off, certainly the idea of a public CVS makes sense.
Again, thank you for your ideas. I will be interested in reactions from others on this forum concerning the best ways to share scripts and develop the software.