Exactly, other languages would use something like "Det är bara människan som utvecklat tal" or "Es ist nur der Mensch, der die Sprache entwickelt hat" depending on language
At least lead is better than mercury or americinium since both of those metals have no business in vitamins but might be used in vicinity in older fire alarms and thermometers.
If we are going worst case and a box of old alarms or thermometers got stored improperly and got crushed into the mix
It's a communist utopia, I would assume the central government has that info regardless if it's a citizen or a government personell. Citizens of other members in the Federation would opt in to the tracking
If you define parameters the first time you (or your parents) use a replicator (which is every thing you ever consume except for social dining) and the replicators sync you should have a quite large library of your tastes which it can use as a filter for when you order new stuff so you don't have to refine the parameters very much.
Good contact is quite fickle if there are any obstructions or even dirt on the skin, but my experience are mostly with the fingertop or earlobe sensors which are quite sensitive due to only using a red led. Does the wrist one use another kind of tech?
If they are traveling in the right direction they can actually take the turn in upwards of 1672 km/h in your example