I was thinking of using the pagedata class to create model items for just storing data which sit in the page tree but have no actual rendering. For example to give them the ability to create a list of authors to populate a dropdown or to be able to associate to a page via the ContentReference which I can then do funky stuff with.

However I was wonder if there are other better ways, or even if using blocks for this might be better. I have read that there are interfaces and objects at a lower level which would mean they don't have to be pages or blocks, but it doesn't seem like these are then easily accessible to edit in the UI, and really all I want is the all properties view for this content data.

Is there a better approach or is the quickest and simplest approach to just use pages or blocks and not create the views?

I think I can probably create some custom base classes to prevent these being draggable to content areas.