I believe he was protecting the uke from his allies. They probably wanted the entire family killed, and the seme agreed to go along with their plan only if he was allowed to save the uke. His decision to become emperor also probably was made in the belief that it would be the only way to protect the uke's life. He truly fell in love with the uke. At least, that's how I like to think. As far as the rape goes, this has a historical setting. The concept of rape=bad is a more modern way of thinking. I'm not saying that makes it okay; I just try not to judge historical stories by modern concepts.
Exactly!
in chapter 5, the uke gets to watch his father get killed by the person he trusts, he gets raped multiple times, and in the end, its told in all seriousness that the seme was doing everything to 'protect' him.
And from what exactly? It falls short even in describing why exactly he had to murder the uke's family.. since the man's like "Oh, I donnu, Its not like I hate anyone..I just want to be emporer, but only now..."