6. Is it possible to store a database of cargo items directly in the app?

Yes, it is possible. Under the tab “Cargo Items”, you can easily add, import, and maintain a database of cargo items:

In EasyCargo, these items can simply be added by entering part of the cargo item’s name when adding an item in the editor, and all of the item’s properties will automatically be prefilled from the database:

Cargo Items database API is also readily available (see the question Is integration via API possible?).