Is there a reason some items bought from the Zen store are delivered straight to you (such as ships going straight to the shipyard, clothes being delivered to the tailor) and others are not?
The actual item types aren't even specific to "in a box" or "not in a box". Some clothes (like Ferengi Jackets) can be sold on the exchange, Some (7of9's suit) can't. Some ships can (D'kora), others (Odyssey) can't.
Why can't every single item on the Z-store be packaged in a Special Requisition Pack - Whatever that can be sold on the exchange? It wouldn't cause PWE to lose money on Zen-store sales (someone has to buy the item in the first place), and may actually be a profitable venture with people actually spending Zen to get something they don't want, so they can raise the EC to get something they do.
The objects in a box, are usually single, repeatable purchases, while the ones that go straight to inventory/shipyard are reclaimable.
I think your idea is extremely bad... If anything there should be less.
I think you may have misunderstood where I was going with this.
There would be no change to the actual items, opening the box would still grant you the reclaimability and account unlocks you get now where relevant, the ONLY change would be that the person spending the money in the Z-store could sell it to someone else for them to redeem.
So you buy an account wide unlock, and sell it for EC, at which point you'll have to invest your Zen again to get the same account wide unlock for yourself?
That's less bad, but the system's not set up for that. The moment you claim an account wide item on one character, not all your characters immediately get it. It remains, for them, on the C-store, needing to be claimed manually, since some of them might be of too low a level to claim the item, or they don't have enough ship/boff/doff slots to accept the item automatically.
So then, rather than doing the difficult thing, adding in new UI elements to distinguish between buying an account wide unlockbox (now there's an interesting word) and claiming an unlocked unlock that can't be sold, wouldn't it just be easier to let people buy zen gift-certificates on the C-store and let them sell those for EC on the exchange?