In the first situation, I assume while you are at school, holding them still would be better than 'escaping' until the public safety comes. For the second, depending on how dangerous, I would still have choked the guy...choking doesn't mean killing.The (first) RNC was at school. And I was asked to explain my behavior after. The explanation would be harder if I had put him unconscious. And I don't know reanimation.
The second RNC was on the street, late in the night. I was asked to stop by friends of mine. And the guy came back to fight again. (Just managed the distance until the taxi.)
The issue with that solutions (choke and snap) may be legal ones... (And in may case, I need a great motivation, or no alternative, to go so far.)
For many of the situations where you aren't willing to choke, snap, or let go, you should be doing something else rather than putting them in one of the holds designed to do those things.