Robert Moses spinning in his grave
See p. 241.
An appoggiatura is an embellishing note or tone preceding an essential melodic note or tone and usually written as a note of smaller size. It often creates a brief dissonance prior to its resolution to the melody's key. 
drop the hook
The Port of Authority
Now more commonly know as the Port Authority, The Port of New York Authority was established in 1921.
- "ARTICLE III There is hereby created "The Port of New York Authority" (for brevity hereinafter referred to as the "Port Authority"), which shall be a body corporate and politic, having the powers and jurisdiction hereinafter enumerated..." 
Pynchon's usage is old school.
For happiness, good luck, fortune, etc.
Another roll-over from the 90s. Sort of the DVD equivalent of the dark web.
even larger question about to lift its trunk
ie the elephant in the room
her backpack ... does seem to run to Himalayan-expedition scale
Pynchon also uses this trope of containers larger on the inside than the outside suggests in Mason & Dixon at page 354
Music track? Frank Sinatra..."Time After Time," beginning the phrase "in the evening when the day is through,".
Indeed, a most poignant lounge music song. Hear Sinatra sing it. The lyrics in question come around early, at the 0:41 mark.
A heavy metal band from Brazil.
Burzum and Mayhem
Both real bands.
among widely reported Ambien hallucinations being numbers of small people busy running around doing a variety of household tasks
These little people are recapped on page 346. Psychobotanist Terrence McKenna postulated the existence of "machine elves" seen while under the influence of DMT:
- Terence McKenna advocated the exploration of altered states of mind via the ingestion of naturally occurring psychedelic substances. For example, and in particular, as facilitated by the ingestion of high doses of psychedelic mushrooms, and DMT, which he believed was the apotheosis of the psychedelic experience. He spoke of meeting entities he described as "jeweled, self-dribbling basketballs" or "self-transforming machine elves" which one can encounter in those states. 
no more fictional reading assignments
Reminds me of Uncle Ives in Mason & Dixon who thinks fiction is immoral: "I cannot I say, energetically enough insist upon the danger of reading these storybooks,— in particular those known as 'Novel.' . . . these irresponsible narratives, that will not distinguish between fact and fancy" (350-51).