Theory is interesting I will say that the common trend in the Manga is if you have ocular Jutsu you've been a bad boy..... But there are a few differences I have. I do agree that Hagomoro definently hasnt told us the whole story, and because he didn't discuss his brother much he may have done something wrong or shameful in regards to him, but I don't think hes going to be the source of conflict or evil, I'd find it more likely he may have done something slightly selfish resulting in his brothers demise, that he because of immense guilt has decided is unforgivable. I think he is however trying to make ammends for whatever he may have done and set the world right, also I think its going way to far to say Hagomoros methods rely on subjugation and power, he split his power rather than giving it all to naruto or sasuke, he divided the ten tails into 9 beasts who he told would one day be unified under someone who would cooperate with them, he divided chakra among people with what I would bet were good intentions the guy has atleast had good intentions, just unplanned results. Also something I'm very curious about if Naruto were related to the other brother not hagomoro, why did Ashura incarnate into him the other incarnates have been direct descendants of the line, also anyone else curious at the lack of mention of Hagomoros Father? Perhaps he is Jashin.