Yes non-consumable is used once and linked to the account in some way and consumables increment something and can be bought again. Local storage is cleared if the user tries to clear it from the phone menu, if you install a new update it won't clear the data. You can't clear it by mistake, they need to do it themselves as if they are uninstalling the game. As for the other stuff, you seem to know more than me about that, I've not used IAP with database but maybe someone else has more information.