Along those same lines... is there a way to make the repository reference existing files without having to go thru the uploader? (I get "A critical error has occurred. Maximum request length exceeded." when trying to upload a file on the server itself).

For instance, Windows media archives .asf files into the clients site and I would like to add those to the repository listing. I haven't found a way to do this.  Ideally, I'd like to have them 'auto-add' to the repository but I'd be happy if I can just 'add' them manually.

The Max request length error sounds like it's a filesize issue which can be adjusted in your web.config. Look for a section about allowing large file uploads and in the httpRuntime line below it adjust the masRequestLength to a number big enough to fit your file size (by default it's set to 8MB). You may also have to add an executionTimeout="xxx" (measured in seconds).

Alternatively you could use a [URL] or [FILEURL] tag in your template (double check the documentation) and point it to the existing file. You'ld have to do each one but it's an option.