Have you ever used Comic Manager? Maybe the features you talk about could be integrated into Comic Manager (some of them are missing, and some can be improved).
Also for the document views, there is this plugin which might help: Plugin: Subwindow organizer
For layer styles management, please see this mockup: Layer Styles: new collections manager UI/UX design inside Layer Styles docker - it’s ugly, but it’s more about usefulness than beauty for now.
About tags for fonts, I don’t think they are planned, but I do think there were some talk about listing fonts used recently somehow on top… or a list of favorites… it’s definitely something to improve upon.