FBI Director Jim Comey's speech definitely hurt Hillary Clinton's chance of becoming the President. Comey called her "extremely careless" and said that someone in her position should have known that what she was doing was against State Department policy. Republican's will latch onto the phrase "extremely careless" and use it against her through the election.
Yes, the FBI director's comments on Hillary Clinton's email practices hurt her presidential election chances. By publicly chastising the former Secretary of State for extreme carelessness in her handling her email, he did considerable damage to Secretary Clinton's reputation. However, the damage is much less significant than criminal charges would have been.
Though FBI Director Comey stated that Hillary Clinton will not be charged for her email server activities, Clinton's campaign will continue to be impacted by the scandal. The public no longer views her as a trustworthy candidate which means that they are less likely to choose her as their presidential candidate.
No, people hostile to the Clintons have been accusing them of all sorts of misdeeds for decades by this point, meaning that most members of the American electorate have already made up their minds about Hilary Clinton. Furthermore, the investigation revolved around technical details that mean little to the average voter, meaning that most people are going to interpret Comey's speech based on their existing beliefs.