Dōgen Zenji (1200 – 1253) was a Japanese Zen Buddhist teacher. See WIKI .
For you suffer fools gladly, seeing you yourselves are wise
2 Corinthians 11:19. Apparently, the American King James Version.
Park Avenue, despite attempts at someone's idea of beautification, has remained, for but the chronically clue-free, the most boring street in the city.
Pynchon aptly admonishing the tyranny of glass superstructure that encroach on the architectural feat of Grand Central Terminal. Carved stone is no match for ironworks, asphalt, and the glass skyscraper home to both Pan Am and MetLife in its life, seen here. 
Julia Richman High
Julia Richman High School is a defunct comprehensive high school in Manhattan, New York. Built in 1923 and located at East 67th Street and Second Avenue, the building was the only public high school in the Upper East Side of New York. The school is named after Julia Richman, the first woman district superintendent of schools in New York City. For much of the school's history it was a girl's high school; it changed to co-educational in 1967. In 1995, after years of academic decline, the city reorganized the school into six separately functioning small schools within a building renamed as the Julia Richman Education Complex. From WIKI.
Edwin Parker "Cy" Twombly, Jr. was an American artist well known for his large-scale, freely scribbled, calligraphic-style graffiti paintings, on solid fields of mostly gray, tan, or off-white colors. WIKI.
- Twombley paintings sell for millions and he is an example of a painter whose works are often bought for financial and/or status reasons by the ultra-rich today.
Massive, expensive piano that has 97 keys and is even larger than the Steinway concert grand. The extra keys, by the way, are on the bass end of the keyboard.
Omar the Owl wall clocks
Cute indeed. You can see one here.
Me, I want a hula hoop
The lyrics to a popular Christmas song by The Chipmunks. A paragraph earlier, Tallis is descdribed as having a "sub-Chipmunk voice."
The men who founded the institutions now merged as Carnegie Mellon were Scottish (Andrew Carnegie) and Scotch-Irish (Andrew Mellon).
Another Chipmunks reference. A running joke throughout the Chipmunks cartoons is that the Chipmunk named Alvin is always late or screwing up. So he is often yelled at.
But Ricky, it's only a hat
An allusion to the TV show I Love Lucy, which often featured matrimonial dispute. Specifically, this line refers to the 1954 episode "Ricky Loses His Temper."
Smith & Wollensky
Smith & Wollensky is the name of several high-end American steakhouses, with locations in New York, Philadelphia, Houston, Columbus, Las Vegas, Miami, Chicago, Boston and Washington D.C. The first Smith and Wollensky steakhouse was founded in 1977 by Alan Stillman, best known for creating T.G.I. Friday's, and Ben Benson, who later opened his own steakhouse at 123 West 52nd Street, in a distinctive building on 49th Street & 3rd Avenue (once occupied by Manny Wolf's Steakhouse). Many of the restaurants have a wooden exterior with its trademark green and white colors. The individual Smith and Wollensky restaurants operate using slightly varied menus. In 1997, Ruth Reichl, then-restaurant reviewer for the New York Times, called Smith & Wollensky "A steakhouse to end all arguments." From WIKI.
They're sending him to Collegiate. Where fuckin else?
Collegiate School is a boys school, grades K-12, on the Upper West Side: 260 West 78th Street. 
the ruling-class polytechnic
The Collegiate School is a polytechnic school, and likely conforms to this definition:
- The institutes of technology and polytechnics have been existing at least since the 18th century, but became popular after World War II with the expansion of technical education, associated with the new needs created by industrialization. An exception is the Ecole Polytechnique, the oldest one in the world, which educates French elites since its foundation in 1794. In some cases, polytechnics or institutes of technology are engineering schools or technical colleges.
A "polytechnic," as Pynchon uses it here, is a school whose curriculum is geared toward a broad and thorough education in the subjects that are necessary to master the Modern World, i.e., specializing in technology or different sorts of technical subjects.
Scream, Blacula, Scream
Scream Blacula Scream is a 1973 blaxploitation horror film, made under the working titles Blacula Is Beautiful and Blacula Lives Again!. This is the only sequel to the 1972 film Blacula. The movie was produced by American International Pictures (AIP) and Power Productions. From WIKI.