| Quote #1
At this stage of the journey
This use of the word "journey" is like a hint early on that our speaker's in the mood for adventure. And the mention of the distance between him and his feelings tells us that our speaker's flight isn't fulfilling his urge for just that. Even though he's hurtling through the air, he's cut off from any sensation of doing so, and he doesn't have anything to do except sit and listen to Muzak.
| Quote #2
where men throw harpoons at something
Even though at this point we're not necessarily sure whether our speaker wants to join these men, we do get a sense of the excitement of their lives, and how different that is from our speaker's day-to-day existence. And that word "probably" is like a hint at the unknown. Whales are these huge, mysterious beasts and our speaker wants to be close to that sense of awe and mystery, not shut up in this metal tube. (He probably wouldn't like being in a submarine either.)
| Quote #3
wanting to kill it,
There's some way that this action, this adventure, this violence, is invigorating. A rough summary: passivity causes detachment; activity brings you close to your alive-ness, even if it's bloody and violent.