I was told that you should blow the steam above the bowl so it clears up and make way for more steam to rise. You're not directly making the food colder, but it helps.
Tempering ice cream is totally a thing and recommended for proper flavor and texture. You should let it sit for 5-10 minutes before consuming, so like too hot food, you can also blow on your too cold ice cream to warm it up!
That's an invalid conclusion. Blowing on ice cream works too, though maybe to a lesser extent. You're still hitting an object of extreme temperature with a barrage of medium-temperature air particles. Heat would still transfer in this scenario, albeit in the opposite direction (heat would transfer from the blown air to the ice cream).