Yes, eBay will eventually phase out all JS and other active contents, only CSS and HTML are allowed.
Your code is nice. One problem: I use one template for all my ebay auctions, and each auction has photos with different sizes. So if I use the same code for photos with different sizes, some of them will be cropped off in preview pan, like this one:
It’s OK to have distorted thumbnails, but I would like to have the preview display whole image. The height of the preview does not need to be constrained, only the width must be 350px. I cannot go into every auction and change the width and height every time because I have hundreds of auctions posted every week. Thanks for helping.