Okay. I'm not known for releasing fabricated evidence, so you should assume I'm telling the truth? That's what you seem to be saying. Assange has released stuff that appears to be genuine in the past, but it's impossible to actually check most of it. I still think that's weak evidence for trusting him.
My attitude on burden of proof is that it's on the people who claim to have obtained documents illegally, without being able to verify them. I also like judging things scientifically, based on the results if true. Clinton says nothing, so the emails must be legit. Clinton casts doubt on the veracity of all the emails, so the emails must be legit and Clinton is untruthful. Doubtless if Clinton said it was all a hoax you'd use that as evidence that she's lying (feel free to correct me if I'm wrong here). My conclusion is that, no matter what Clinton said, you'd think the emails were all legit. This means that you can't take anything she says or doesn't say as evidence for the emails. If not, please tell me what Clinton could have said that would convince you.
"From everything I've seen" is probably not the way I should have put it, since the evidence I've seen is a bit thin, but it does appear that the DNC servers were hacked by someone with Russian connections. We do know that most such leaks are internal, and that's what I'd assume in the absence of evidence otherwise. Obama is certain enough that it was a Russian state-sponsored attack to create a diplomatic incident about it, FWIW.
I seem to have two advantages over you in interpreting Assange's story: I know a little about how rape victims often behave, and I don't know the Swedish legal system so I don't make assumptions. I see nothing suspicious about the victims' behavior or the Swedish legal system. Rape's a tough crime to prove. However, Sweden, Interpol, and the UK thought that the evidence of the rape was enough to extradite.
I hadn't heard of Assange asking the US for promises. He did ask the Swedish government for assurances that they could not legally provide, since that would involve the executive branch committing the judiciary branch to something. He did annoy a lot of people in the US, and I'd suspect that lots of them were talking about kidnapping or killing him in their private conversations. Obviously, we can't kill Assange with a drone, so Clinton wasn't serious.
As for the mountain of evidence, people have been pointing me at a lot of mountains I can't see, and failing to deliver when I ask for a pointer to a pebble. It's actually kind of fun, calling people out on things they can't support.
So, what you're pointing at is emails and documents that were likely obtained by the Russian government, or at least someone in Russia, which means there's no reason to trust them. They're posted by a guy who has been making up stories about the US to the point where he doesn't like it (superpowers get people saying wild things about them). In any case, they were provided by one or more criminals or as an act of war, and transmitted through someone I don't trust. That isn't very good evidence of authenticity.