I will arise and go now, and go to Innisfree, (1)
The speaker is really making his move, and although we don't know right away that he's going alone, it soon becomes clear. Plus, there's no we here. His first goal is a solitary one.
And live alone in the bee-loud glade. (4)
There you have it. If you have opposable thumbs and the ability to communicate through language, you're not invited.
And I shall have some peace there, for peace comes dropping slow, (5)
This is sort of a peace-and-quiet announcement, like, "I need to get away from all of you so I'll finally be content."
I will arise and go now, for always night and day (9)
Repeating this line shows us that the speaker is serious about getting his alone time. He has had it up to here with the hustle and bustle.