What you said is right.
Besides, regarding your last doubt. I think I can answer some questions. Items are classified according to whether they can be directly used by characters. It's better to understand it this way based on the props and materials in the game. Whisky and beer, these foods, can be directly provided to the character in the inventory.
The rest of the food includes basic items such as fish, meat, vegetables, grains, and advanced fish cakes. None of them can be used directly Of course, when you go on a date, you can treat the NPC with food.