does anyone know of a plugin for mass editing of settings on a multisite installation? Something like Plugin Commander for Settings?
i think this is what you looking for: http://wordpress.org/extend/plugins/yd-wpmu-sitewide-options/
I'm not sure if this really answers your question, but have you looked at CheezCAP?
It's a framework to allow a theme to register options and settings panels on the fly, so that on a multi-site install you can more easily add options to the themes across the board, and manage the settings on a site-by-site basis.
Doesn't quite do what you're looking for, though...