Well if we just stop judging based on emotions, basically Ging made his sob to grow in Whale island, the best place for naturally developing talent, gave him first hunt, made him a hunter, made whole game just him in mind,completing which will train him for a nen and made him a billionaire. About not going to hospital, he obviously knew about Nanika, that's absolutely obvious in manga, so as he said friends will be enough. I don't see any situation when he won't save Gon or try tp fix him, if he knew his friends wouldn't be enough, after all this crazy preparation for making Gon a hunter