Congratulations on your impressive chinning - but based on nearly every article I have ever read (and based on personal experience), exhalation is most comfortably done with the exertion phase of the lift.
So for your example, yes, exhale as the weight goes away from you for the bench press, but you have the curls backwards - EXHALE when you CONTRACT the biceps (exertion phase), INHALE when you lower the weight - it's a little confusing to talk about "when the weight is away from you" when you're comparing a pushing and a pulling exercise.
Your example of the boxer who would exhale when he throws a punch is correct - because throwing that punch IS the exertion phase.
That link to the article you posted doesn't really back you up with any proof or explanation - it's just someone else saying the same thing as you. Someone who says things like: "Chin-up are actually a back exercise - they widen your latissimus dorsi muscle - that's "lats" to us in the know." LOL!