Yes.
> I bet the existence of that instinct has far less empirical support than the pain consciousness of newborn babies.
I'll take that bet. Why do you think human children play with dolls?
> People can be tricked.
Indeed.
> A corpse is a "dead person" like a puddle of water is "melted ice".
You're kind of making my point for me here. A corpse is an inanimate object. An inanimate object cannot be a person. A corpse was a person, but when that person died it ceased to be a person just as when ice melts it ceases to be ice. When a person dies, when ice melts, they cease to exhibit any of the distinguishing properties that made them a person or that made them ice.
> It is established that human babies develop into human adults.
Sure, but that in and of itself does not make them people any more than the fact that people die makes live people corpses. A live person will some day become a corpse, but while it is alive it is not yet a corpse. A baby will some day become a person, but while it is a baby it may or may not be a person.
> Their pain and other distinctly human responses resemble the adult forms profoundly.
That's simply not true. A baby's response to pain is all but indistinguishable from its being, say, hungry, or just in a bad mood, whereas in adults these are pretty easily distinguished. But even if it were true, so what? You could make an automaton that mimicked adult responses to pain, but that automaton would not feel pain. You can't conclude anything about subjective experience from I/O behavior alone.
Look, I'm not saying that babies don't feel pain. I think they probably do. All I'm saying is that it's not the slam-dunk that many people here seem to think it is.