As for adding external images and videos to save bandwidth - this can already be done. You can add images and videos (internal or external) using the WYSIWYG editor, or with any number of content plugins which now also apply to SR reviews. For example, I created a review yesterday and added additional images in the review with JCE WYSIWYG editor.
Adding a specific gallery content type to simple review is no small request and will likely be a low priority for row1. I think an indirect good point from the link you posted was that the review was in the main content area, and the gallery, and comments appear to be in more of a module location. It looks like the facebook links at the end of the review are the end of the main page, and everything below could be more of a module position.
1) It would be great if Simple Review could mimic this by having the comments in a module to be placed in custom areas of the template.
2) it would be great if somehow we could assign modules only to specific reviews. Right now we can only assign modules to show on simple review pages or not but cannot specify exact reviews. If you could - you could just go get a gallery module and solve this problem for you.
But, since for now you cannot, the only way to do this would be to create a few new fields in your category for additional photos and video links, then customize your review template to display them at the bottom as you want.