I didn't hear the whole thing but it was something along the lines of "I've learned as a leader it's not why you make the decisions but that you make a decision".
I remember it was something like "whether you're right or wrong it's time to make a decision".
I think the federal agent was just someone who had been assigned to shadow Nucky, perhaps in light of new information that Van Alden had provided.
Jimmy clearly showed that he had trouble with killing his old friend. I think he still kind of liked him too much. So I don't think Jimmy was giving him a kiss of death, he was actually trying to save him by making him look in the direction of where the assassin would come from. This way, he wouldn't lose face by canceling the hit, but still trying to prevent it from succeeding.
