When I was a small boy, maybe about 9, I would sometimes go to stores in my pajamas if I was very sick. And it wasn't uncommon for small boys that age to go into the women's room with their mothers for security reasons. I saw both of those with other boys too. But I don't know what people do today.
I have come across all those things that you mentioned, but less so in the cities. What I do remember that would not be allowed today, was going to the shop to buy beer and cigarettes for my late father. (A bottle of Watney's brown ale and 10 senior service). I was about 7 at the time.