We used to play with liquid mercury metal when I was a kid. Big 5-lb jars of it.
My impression is that it is essentially harmless unless heated (fumes). You don't want to swallow it.
Otherwise, much ado about nothing.
If they caught kids making "silver pennies" with mercury there would be a full-scale haz-mat evacuation.
Should have seen my basement, circa 1965.
--Boris
The mercury from a "silver penny" my brother showed me how to make was absorbed by my skin when I put it in my pocket. The ensuing illness was very severe, and I have had neurological problems ever since. Don't pooh-pooh mercury's toxicity. Very bad stuff.