Well both of these questions were answered in the post, but I don't mind repeating. Saladin says Rasputin is no longer a warmind because warminds are made to protect humanity at all costs; Rasputin is no longer does that, and has created his own path to defeat the Darkness now Rasputin has strict protocols not to let anyone use SIVA, as it could yield disastrous results. So Rasputin kills anyone who tries to take it and activates the self-destruct switch on SIVA if anyone manages to get to it through his defenses. We don't know why he let the Fallen get SIVA, or why he didn't take complete control over them after they stupidly integrated themselves

That he evolved out of programming. He is now a self thinking interlect like any other. Which means he has his own motives and fears right now. The only reason he trusts guardians was because he was forced too. He did the math they where only force able to keep ejecting intruders into his systems

I have two answers. The first is fairly simple. Rasputin was somehow able to override his own programming and moral systems to abandon humanity and shut down. By doing this, he has ascended past what a Warmind is. As for the second, Rasputin mistrusted the Traveler in the Golden Age. The first thing he detects when he woke up was more than a hundred signatures with the Traveler's energy in Sector 17 (the cosmodrome), trying to get to his stuff. He immediately retaliated.