At the very least you're left clamoring at your screen for the option to just tell her ,"Look paarth helped me , he says he's gonna turn the others to the way , but if he slips up I'm on him like stink on sh!t." But no , you get the huge WTF moment of do it or else.
Actually she knows quite well that Paarth helped you. She doesn't care, and flat-out tells you they doesn't need his help anymore. http://imperial-library.info/content/atlas-dragons says he should die, and so they want him to die, end of story as far as they're concerned.
Thats just makes them sound even more irresponsible. They could have at least called him to restrain him or reprimand him for his actions.
Restrain him? What are they, jailers? It's not like it's illegal to use thu'um if you're not a Greybeard, and it's not like only Greybeards control knowledge of thu'um (that can, in fact, be a point of oddity in the game; thu'um was used quite a lot among the Nords of Skyrim in the previous Eras, while Skyrim shows it restricted to just the Greybeards and some special individuals).
Vendatta is the word used by the GB. Your sentiments clearly lie with the GB.
My sentiments lie with the Greybeards because they're the most forthcoming with me and are willing to work with me to do what must be done to take care of the dragons' threat. They teach me what they know, and do not demand I follow their way. Despite concerns, they still teach me the Clear Skies shout so I can meet Paarthurnax. After voicing their displeasure about you wanting to learn Dragonrend, they still tell you where to look for the Elder Scroll so you can go back in time to learn it. After voicing their displeasure about getting involved with the civil war, they still use their influence at your request to get both sides to the table for a temporary cease-fire so the dragons can be dealt with.
The Blades, on the otherhand, operate on a need-to-know basis. If they don't think you need to know something, they won't tell you. Delphine gets Farengar to ask you to dive into a dangerous ruin to get a stone tablet (which might not have even existed), and won't tell you what it is or what it's for. She sends you blind into the Thalmor Embassy without any clear goal (besides 'look for any info they have on the dragons'), which almost gets you and her informant killed. She also refuses to believe you when you tell her they know nothing, until you call her on her stupidity and she apologizes. They'll then have you figure out the puzzles to reach Sky Haven Temple, and open it up with your blood, before making themselves at home. Then they say that the Blades need to be rebuilt and tell you to bring potential recruits. They'll sit there and accept Paarthurnax's help, until they deem his usefulness to be over then promptly demand you kill him.
Exactly. They don't do anything about him, even though they're probably aware his duel has sparked something that has caused a lot of dead Nords.
If anyone has seen Kill Bill, there was a character.. Hatori Hanzo. A pacifist blacksmith/swordsman. Once he heard about his former student (Bill) turning bad, he dropped some of his oaths and intervened. He felt responsible for even teaching him. The Greybeards can't even seem to do that.
Hatori Hanzo's oath was against making swords. Even when he breaks that oath, he doesn't do anything about Bill himself, he lets The Bride do it. He also didn't do anything on his own, and only did so after she pushed the issue.
Last I knew, Elisif didn't show herself to be worthy and plead for the Greybeards to teach her so she could exact justice/vengeance on her husband's murderer (but even still, they do teach you despite you not following the Way of the Voice, and as mentioned before, the Greybeards aren't the only way people can learn thu'um), so Kill Bill isn't exactly a good comparison.