Suggestion: simple document preview
This is a feature that I liked from Qiqqa, where by simply posing the cursor you could see an image of the first page of the document. I don't now how doable this feature can be incorporated in Zotero as it does not have any embedded document reader, but it would be really helpful to have any kind of simple document preview, specially for pdf's. Thank you.
https://github.com/mronkko/ZoteroQuickLook
It is a huge help for me and a great time saver.