I was definitely impressed by how politely you were answering all of the anonymous asks. Especially as I imagine the majority were from people who didn't realise they had to ask privately, and were not deliberately trying to bypass your rules.
As for the images, what I meant was that the website itself will not display images, unlike how DWP was set up to show you what you were downloading before actually having to download the file. I believe that the .zip files on the new website still contain images of what the files are, but you still have to download these .zip files in order to have access to the image file. Therefore, it doesn't make the new site that much different to using a SFS directory, because the new site is literally just a list of file names.
I will keep an eye on the new site to see if any changes are made, but I doubt it. After observing the way you are handling your files and the people wanting to access them I feel more inclined to want to use your site over the official alternative to DWP. I also completely understand and respect the need to keep the link private. In fact, I think it's far smarter than having a public site that people can target. I found your email address off your tumblr and will email you now. Perhaps you might like to create a FAQ page on your tumblr or something, so that people understand the rules to access the SFS folder, and maybe link to your email address as an alternative.