Can I tell if my content bookmarks on import?

There's nothing we can tell at import in that regard. Specifically, all bookmarking concepts are handled at runtime and in whatever way the content wants. Most pieces of content would put that data in the cmi.location data model element, but bookmarking concepts could be accomplished in other ways as well (suspend_data). So, there simply isn't a way to be sure whether a not a course is bookmarking programmatically.