So I finished the major changes I had in mind for the OPML Support extension. I added support for regular bookmarks, a few options (whether to import/export livemarks, bookmarks, or both; option to import/export livemarks as regular bookmarks; option to import/export nested vs. flat), and a few bug fixes.

If you’ve had problems in the past with OPML files that OPML Support creates being non-valid XML, download the new version, which has a much stricter check for illegal characters in link titles and descriptions.