Hi EA,
1) Yes, you can turn it off on posts you don't want by adding [ps-skip] to the post
2) The only field that you have available is the Gallery Name: [image_gallery_name] If you scroll down in the Layout Editor and look for the Gallery Viewer Fields in the right-hand column, you can get a little explanation for that and some other fields that would be helpful for what you're trying to do.
So, I don't really like the Auto-Add feature because it adds galleries everywhere! So, if you are building theses posts from uploaded images the the Extend functionality, you can just add the [photosmash] shortcode to the Layout that you are using for the upload. That will create a new gallery for you in the Post just as if you had written the post and added the shortcode that way.
Some ideas on the Facebook photo albums...Does the Gallery Viewer get you most of the way there? If not all the way, what is it missing?
One way to create your own Gallery Index page is to add shortcodes for each of the galleries you're wanting to display to a page and specify a specific image ID that you want to show, and you can limit the display to 1 image. It's a manual process, so it might not be what you're looking for. The Gallery Viewer automatically adds new galleries anytime one has images in them.
Let me now a little more of what you're trying to do and i'll think on it.
BTW, the iPhone App is almost done...hope you've got an iPhone or an iPod-Touch! I'm really excited about it. It's not ultra-cool like Angry Birds, but it does some nice PhotoSmash-y like things.
Cheers,
Byron