> the images should also be rotated to their proper orientation

there's a rotate button when you click through to the detail page. We're tracking where images get rotated to, and setting the orientation according to that. It's still a bit buggy, but we're getting there

> the technique of OCR and how a large hashtag-watermark can obstruct such a technique

We're running OCR over non-watermarked versions. We're hoping to have a search function up later today

Thanks for the links -- we'll look at them, and see what we can use