You asked more than one question so I have had to edit it down to just one, focussing on the point of view of this excellent dystopian story. Well, in a story where there are no characters whatsover - because they have all been slaughtered by some form of future super weapon - it is clear that the point of view is third person omniscient. This point of view is adopted when the narrator takes a God-like position and can see everything from every perspective. This explains the way we are able to zoom around the inside and outside of the house with ease and see and hear all that is going on.
Of course, this point of view is a careful choice of Bradbury's to ensure that we as readers see this amazingly technologically advanced house go through its normal daily motions. But there is a central irony that Bradbury establishes very clearly, and this is partly achieved through the poem that the computer recites. Bradbury seems to be pointing us towards the fact that the human species is immensely fragile and in a tenuous position. The extent of our technology does not matter, for we are able to extinguish ourselves at the press of a button so easily. The truth of this is displayed in the poem:
Not one would mind, neither bird nor tree,
If mankind perished utterly;
And Spring herself, when she woke at dawn
Would scarcely know that we were gone.
In this world, Bradbury, through third person omniscient point of view, presents us with the true irony of our condition as humans. Yes, we are incredibly advanced, and this will only continue, but let that not make us arrogant as to forget our true delicate place in the scheme of things.