For me Omnifocus would become the killer app if it would allow non-actionable items in projects - similar to tasks, but lets say dummy tasks for storing info.
Those are not really for keeping project reference, but to keep things that are not actionable yet or you need to be reminded on when planning actionable items. If that’s not within the philosophy, then severely improve the note editor.
That and on the mac I would like to see really easy navigation and editing of the whole omnifocus file as a big outline (lets say in project view), right now it still feels clunky and often have resort to using a pointing device.
For a bit of context, I’ve fell off the Omnifocus bandwagon for 6 months and have been using emacs’ org-mode, and I can see how those two very basic features would make Omnifocus a bit more useful (I could also add the “scheduled date” functionality to the list but I won’t). I still appreciate of Omnifocus the integration, scriptability, mail drop, and easy email triage eg. with Airmail - but on the basic tasks I always feel I’m slowed down by the interface.