For both the sake of organization and theme, I think it would be nice if there were folders available that could fit both documents (newspapers, flyers, etc.) as well as photographs. Perhaps ones you could put titles on. Dossiers and such are very themely and are by definition a collection of items. I believe it would be cool to be able to have single object deliverables for a more professional vibe, as well giving people the opportunity to declutter their stacks of such items.
In addition, it would be nice to see more stores have letters, e-prints, and such reliably stocked and more commonly available. I understand the exclusivity of certain items pushes for more player transactions, but when it comes to things such as canvases or writing tools that only fuel creativity, I think it would be nice to have those more accessible to the same end of promoting player interaction. I could see it being a bit discouraging to the immy who cares to simply leave someone a note that they have typically travel all the way to Green for a single letter or invest in two separate gadgets to do so.