I must say i have not read the DNC leaks nor can i consider them 100% true at this point. Nevertheless you could argue that Sanders (and to a point O'Malley) did not receive the full support that Clinton had when it came to the run for the nomination. Partially it is because the Clintons are simply more influential in the party and just plain more well known (how many people knew who bernie was in 14?). I am not saying it was totally rigid but i will say i do however feel that it was stackted in her favor to an extent (how large is debatable). Likewise if the voters do feel it was rigid then that causes distrust of the party shich is only natural.
The Democratic Party didn't do anything to hurt Senator Sanders' campaign, and it didn't do anything to give an advantage to Secretary Clinton. One might argue about debate scheduling, but that's both circumstantial, a matter of opinion, and hardly out of the ordinary.
The activist comment is that to a large degree Clinton did not have the same type of activists suppprt her that Bernie had and likewise mamy activist (3rd party progressives for example) liked him for being a progressive outsider who was willing to disagree with the party if it was to support american progressive causes.
By any definition, Secretary Clinton is as much an activist for social change as any other candidate. I'm not sure what you're getting at. Are you criticizing her because she's not an activist (she is), or are you criticizing her because she's not progressive enough? They're two separate issues.
Likewise i have to say whether fair or not Clinton is getting some flak for support of things like Doma, the tpp, 3 strike policies and other things of the past which scare some progressives even if she has supposedly changed views (whether you believe that is personal opinion).
Hillary Clinton wasn't in a position to vote on DOMA at the time of its passage, but regardless, some would argue it was better than the alternative of a constitutional amendment. In addition, Bernie Sanders was on record against same-sex marriage nearly ten year after DOMA's passage. You'd be hard-pressed finding an American politician who has been consistently in favor of gay rights. The vast majority of Americans have switched from one position to the other. One shouldn't be punished for his or her history on the issue after coming around on gay rights like we asked. With regard to just this issue, what more do people want?
With regard to the TPP in its current form, Secretary Clinton was never on record in favor of it; the controversy was she didn't want to undermine President Obama while it was being negotiated and wouldn't take a position. She did come out against it after being pressed on the issue. For as long as she's had a public opinion on it, she's been relatively consistent in being against the TPP. One might point to positive things she said about it during her time as Secretary of State, but much of what you find will reference what she said she hoped it would be and was before or in the middle of its synthesis.
I'm not saying there aren't things to give liberals some pause, but these aren't them, and they're hardly relevant anymore in a general election against Donald Trump.