As far as point one goes, in a cause-and-effect sense, I think she does share some responsibility for the loss. She was the candidate, and strategic decision-making in a razor-close election could tip the election one way or the other. I could easily imagine a world where different decisions could have changed the outcome (though such decisions would not have been knowable prior to election day). As to the first part of the first point, I think it is silly to say she should not have been nominated.
As for the second part, I think Bernie definitely should have been allowed to run. But I also think he shares some responsibility for her loss. Bernie knew that Hillary was not "corrupt" in any reasonable sense of the word, and also knew that attacks implying otherwise would do nothing but hurt Hillary in the general election. Yet he went forward with such attacks with knowledge of the directionality of those consequences. This line of attack resulted in otherwise reasonable people parroting such attacks, which not only reduced enthusiasm for Hillary, but made Trump's dishonest attacks on Hillary more effective later in the fall. I could easily imagine a world where Hillary would have won absent such attacks, given that the election was decided by less than a point.
So both are partly responsible. I ultimately think Bernie's attacks deserve a bit more blame than Hillary's campaign decisions, since hindsight is always 20/20 with respect to campaign decisions (whereas Bernie knew at the time of his attacks that they would hurt her in the general, and chose to risk it anyway). But both her campaign decisions and his attacks were far from the only causes of the loss (given Comey, the media's obsession on emails, Russia's email hacking, etc). I think all reasonable causes should be on the table for discussion, so we can learn from the mistakes that were made.
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