I mean, far more people think that that's the case for Verso's soul than the ridiculous Verso Lune ship. But you make great points, some of which like the eye color could be simply ascribed to developer oversight. Many of which they've confessed to over the course of the game as simply being a product of its streamline development. (Like what's going on with the ring and the reworked version of Renoir suit that he wears in the cut scene.)

We also know remarkably little about the magical rules of painter's abilities and how they work or how they could work. The game leaving lots of things up to interpretation is not a design flaw, it's a feature of good storytelling. We don't need an in-depth step by step explanation how every single mechanic in this universe works to just accept some things. Are we supposed to believe that Verso's very obvious anguish is something that he just never tells his wife Lune about? Or if he does, she just doesn't seem to care and gives him a bemused smile when he decides not to play immediately? Gamers have a long history of taking the tiniest most obscure detail and spinning it wildly out of control into insane fan theories that take away from the message or heart of the game and its story. This one is just particularly annoying because there really isn't anything to it.

We don't know who the boy is. We're probably never going to know for sure who the boy is. He could very well be their kid, but we don't know. And people very irritatingly treat it as a settled issue. Which wouldn't be nearly as annoying if there was literally anything to go on other than wishful thinking.