I agree with you here. The Blades are worthless now and Paarthurnax actually helps you defeat the other dragons. I love him and wouldn't want to kill him off for a couple of crappy Blades quests. He is an awesome old soul and I like the conversations you had with him.
I like the blades just because it reminds me of my Oblivion character who became part of the blades but I agree with you with Paarthunax. He's a good talker and I kept him alive. The blades aren't what they used to be.
I think I may investigate making a mod to verbally dress-down the Blades into submission for their brash hubris once the CK comes out.
Of course, no voice work for the dialogue, but the "Voiceless Dialogue Breaks Immersion" crowd can go drink milk.
I will look for this mod. I think another option to their little quest or whatever who make it easier though. When they sit there and tell you to go kill him there should be another option that says, "Ok, I killed him." Then they go on about their day with the normal congratulations, he deserved it speech that is already made for them to say. Not like they are ever going to be able to go to the Throat of the World and see for themselves and Paarthunax doesn't ever come down since he stays to himself doing his meditation. Seems like an easy fix to me.