| Quote #4
we are laid asleep
The speaker's trance-like state allows him to become more spiritually awakened. His body is irrelevant, and he "become[s] a living soul."
| Quote #5
While with an eye made quiet by the power
The harmony, or beautiful balance, that the speaker remembers in the "beauteous forms" makes his "eye" "quiet." He's not distracted by his physical surroundings. There could also be a pun in these lines. His physical "eye" is "made quiet," but so is his "I". His sense of himself, or his ego, is quieted. He can see beyond himself when he's in this meditative state.
| Quote #6
And I have felt
The speaker has learned to sense a "presence" in nature. It's awe-inspiring, but it's also "disturb[ing]." Why "disturb[ing]" if it fills him with "joy"? Maybe because it's so "sublime" – so great and so incomprehensible – that he has trouble processing it. That could be "disturb[ing]."