I don't know what point of mine you are trying to disagree with, or what you are getting at. You seem to be missing the forest for the trees.
Everything you have asked about has a very straightforward answer, but you lack the philosophical context to see that.
It's like asking a chemist to explain molecular bonds, when you don't even know that atoms exist.
As I've said, the proper principle of government is to protect individuals from the initiation of force by others.
Since the reasons for this principle are out of the scope of this discussion, yes, you could certainly find some way to appear to pick on it and score points, yet actually fail to do so successfully.
Nonetheless, correctly applying this principle means that if something is always a poison to everyone, it's not a legitimate product. There is no legitimate use. Producing it and selling it is simply initiating force.
On the other hand, if something is a legitimate food, it's fine to sell it.
There is a separate question about allergens. It is an allergic person's responsibility to make sure they don't ingest allergens.
The government forcing people to label things is an initiation of force and a violation of rights.
Absent such regulation, there would still be plenty of food producers who make information about food content publicly available, since it is needed by their customers who have allergies, and for other reasons.
In the cases where food producers do not publish their ingredients (in which case, probably nobody should consume the food...), people with allergies would just be out of luck.
Everything you have asked about has a very straightforward answer, but you lack the philosophical context to see that.
It's like asking a chemist to explain molecular bonds, when you don't even know that atoms exist.
As I've said, the proper principle of government is to protect individuals from the initiation of force by others.
Since the reasons for this principle are out of the scope of this discussion, yes, you could certainly find some way to appear to pick on it and score points, yet actually fail to do so successfully.
Nonetheless, correctly applying this principle means that if something is always a poison to everyone, it's not a legitimate product. There is no legitimate use. Producing it and selling it is simply initiating force.
On the other hand, if something is a legitimate food, it's fine to sell it.
There is a separate question about allergens. It is an allergic person's responsibility to make sure they don't ingest allergens.
The government forcing people to label things is an initiation of force and a violation of rights.
Absent such regulation, there would still be plenty of food producers who make information about food content publicly available, since it is needed by their customers who have allergies, and for other reasons.
In the cases where food producers do not publish their ingredients (in which case, probably nobody should consume the food...), people with allergies would just be out of luck.