Comey tried to blackmail Trump. Mueller I think got in over his head with the U1 problem and saw a way to seek redemption and Rosenstein was the gatekeeper for Trump. All of this is just my opinion at this time. Accept Comey. Comey did try to blackmail Trump with the dossier. I believe that is pretty factual.
I admit I am trying to absorb a ton of information into a middle aged brain. ( I have never claimed to be a rocket scientist for the record)