I have mentioned this before but not in the suggestion thread so one more time.
I find the toggling back and forth on the "Enable Optional eBay Gallery Images" to be a major pain. Of course I want my images to appear in ebay's scrolling gallery beneath the header image why wouldn't you?
To create a new listing from an old listing (create similar) when selecting images you first have to un-click the " Enable Optional eBay Gallery Images" box or go through a couple of additional clicks to delete all images, select the new images then re-click the "Enable Optional eBay Gallery Images" box. For me I often forget to re-click the box resulting in having to close the listing edit and re-post.
I have tried just using the " Enable Optional eBay Gallery Images" section and not adding the images in the above section, since I don't care if I have the images duplicated in the body of my listings. I though this was working pretty well until I discovered that when I import the listings to ecommerce it only sends the header image unless I put images in both sections.
I know that some folks want images embedded in their listing and don't want those showing up in the scrolling gallery but there has to be some way to improve this. Maybe a profile option or general settings option.