Delphine is a bitch. She's got good reasons to be a bitch, and I can sympathize with her plight, but that doesn't make her any less an unlikable bitch. And never underestimate the ability for gamers to take offense to being given ultimatums by obsolete nobodies during the course of saving the entire world and every mortal soul in it."
"This dragon is single-wingedly responsible for mankind overthrowing the rule of the Dragon Cult, teaching the Voice to humans, and has basically been guarding the door to Alduin's cell for all of recorded history while preaching a pacifist creed and conquering his own evil nature. Kill him because he once did bad things so long ago that no mortal can possibly still be affected by them. And if you don't chop-chop and do what I say, I'm gonna totally ignore how I know that you're the only hope of stopping Alduin and sulk in my sweet new temple. That you opened up for me. And then I won't talk to you anymore, so there. Nyah."
"The Blades are wise not to trust me." - Paarthurnax
Paarthurnax, doesn't fault the Blades. The Blades are following their oaths, they've gone back to being Dragon slayers. Them wanting to slay Paathurnax isn't anything different. Dragonguard wanted to slay him too. It isn't black and white, Paarthurnax isn't completely peaceful, nor is he good. Bethesda's theme seems to be the grey area when it comes to split choices in Skyrim.
Paarthurnax taught the voice to three people or it was Kyne depending on which is correct, but he didn't help mankind overthrow the Dragons. He left them to their fate, he didn't stand with them. Mankind created their own shout, and used an elder scroll to get rid of Alduin. The Akaviri killed majority of dragons. Paarthurnax betrayed Alduin, then he joined mankind after Alduin's defeat.
I didn't fault the Blades for their desire to slay Paarthurnax as they are sworn slayers of dragons, that's what they do. Thus Delphine was annoying but not hated by me.
My character doesn't really believe in fate, rather believing that the choices he encounters that affect his life are his own and only his own to make. He decides to face Alduin not because some book says he will, but rather because it's the only way he will live up to his promise to save the people who are close to him and are really the only family he knows any more. He doesn't put any more stock in what fate says he should do than he does in people giving him ultimatums. We all make choices.
Delphine's past is one that would justify anger at the world as a whole. Raido's past is not that much different in that twice in his life before the age of 20 he witnessed the deaths of everyone that meant anything to him. Powerless to stop it, twice he saw his entire world get destroyed. His eternal internal struggle is the battle inside not to let anger and hate take over. Kodlak is the person that helped him realize that there is a very fine and precarious line between questing for justice and being consumed by vengeance., and just how easy it is to slide from the former into the latter. Raido sees the same struggle going on again whether or not the Blades see it too.
Raido's oath is to those dear to him to put everything on the line to fight to save them, and he makes good on it. If some people aren't fully ecstatic about the way he does it, then so be it. We all make choices. That's a "them" problem not a "him" problem.
If Delphine and Esbern want to kill Paarthurnax, then Raido will not try and stop them, but he won't be involved in it either. Should they choose that his decision means their relationship with him is over, again that's a "them" problem. If Paarthurnax eventually gives Raido cause to take him out, then he'll step up and do it but as of now that's not the case. In this story, everyone is required to make sacrifices. The Blades not getting their way with Paarthurnax might just be theirs.
I can't fault Delphine for her view on the world and her desire to carry out her oath and certainly can't hate her for it. I might see it as an irrational oversimplification of her place in the world at large, but I can understand where she is coming from.
Ancano on the other hand is just an arrogant d*ck.