Here's what may sound like a dumb question but..say I have a project called xxx and then export it as yyy does that mean that xxx project should still be there? IOW is it like doing a "save as" where you now have the original and the saved as one?
Yes and no
, if I understand you correctly.
Aperture is completely non-destructive. It's actually moderately difficult to remove things, particular Images. Conceptually, Aperture is a place for storing, developing, and publishing digital photographs. When you publish (export, print) you in no way change anything inside Aperture except that some actions are recorded as having been done (viz.: "emailed", "exported", "printed", "ordered as print", "ordered as book") -- but you are creating a file or set of files outside of Aperture. ("Export" means "make me an image-format file".)
The answer to your first question is: when you export you must name the files and Finder folders being created, but those names are not applied to any Images or Folders (or Projects or Albums) inside your Aperture Library.
The genius of Aperture is that your Image Adjustments (a/k/a "edits") are saved as text instructions to be applied on-the-fly to your never-altered Master file in order to produce Images as needed. This uses computational power to minimize storage space needs. It is only when you need to share your adjusted Images with other programs (what I refer to as "publish"), that Aperture creates and saves to disk a full-size image-format file.
So, going back your metaphor, it's not so much "Save as ... " as it is (again) "Make me a sharable image-format file" from this pair of digital negative (Master) and adjustment instructions (Version)".