I think the dynamic definitely makes a difference. My kids have never fought— not when alone, not on long car trips, truly never. I have had no concerns with leaving them home together. My husband and I have even travelled outside of the country and they have been fine.
(I do realize this is the Dis and I’m opening myself up to the sarcastic “Dis parent of perfect kids” stereotype. I definitely do not think my kids are perfect. They have plenty of flaws, but fighting with each other is truly not one of them. I actually find it very odd that they don’t ever argue and have never had any real conflict. My siblings and I fought horribly, teased each other, and were even physically violent.)
Yes. I was babysitting infants and toddlers when I was 10. So I certainly believe that the average well behaved 10 year old should be capable of taking care of themselves for an hour.
Ours was the same, but was 3rd grade I think. They would not allow the child off the bus unless they physically saw the parent. So if you were in the bathroom or changing a diaper or something the bus would be out there honking.