This is a fantastic set of suggestions. Anybody living off the land for an extended period of time is going to have some method of preserving their food, and it could be a natural extension of the cooking skill. Want to smoke your meats? Cooking level 2 with a fire. Making a strawberry preserve? Cooking level 4, with a jar, a full kettle, a heat source, and some sugar. Some of these ideas (in theory) shouldn't be too hard to mod in to the game, at least not if I'm reading too much in to things. A lot of them could just come down to advanced recipes.