I am not sure why no-one has responded, but many of your ideas sound very good.
I think there are many people who have a large amount of photos and other media files to offer, some already on the web under free license. But they might feel hesitant to upload one-hundred picture.
I, with help from others, am indeed creating some sound files for each of basic Japanese letters and some compounds to be used in Japanese language wikibook. There are about 100 of them. I am very sure there will be others, if not yet, doing very similar things for similar projects. So I find a batch uploader would be very helpful for others like me.
Tomos