Headscratchers / Star Ocean

• What makes the devs decide which foods restore HP or MP to either one character or the entire party? Why would something like a sandwich or a glass of juice work on everyone at a time, while entire pies, cakes, and pizzas can only be consumed by one person each?

• Why do Phia and T'nique require two remaining party slots instead of one each? That would make sense if that's still to reserve a space for one of the mandatory characters, but by the time you can recruit them, Millie and Ronyx are already both in your party. Just what sets them apart from Pericci and Welch?