I would think that Google can completely crawl an XTF collection as long as there is a browse page with facets it can crawl through. I have used Cocoon for a few EAD-based sites, and search robots have been able to access data through facets in the search results page and by following links in records of individual items that are generated from physical facets and controlled access terms.
Duh. Thanks, Joyce :)
I believe you can find Michelle's CSS and XSLT for the printer friendly version on the EAD Helper Tools page space for shared stylesheets: