Your comments in week 7 are elaborated in your week 8 reflections, and they raise several points that are worth pursuing further. You will find quite interesting the book "The Fourth Dimension and Non-Euclidean Geometry in Modern Art" by Linda Dalrymple Henderson. I think that Alison Tarbox or Anya Weber has my copy of it now, but there should be another in the Rockefeller Library since it is a fine volume in art history. The author has done more recent work on the Russian schools of art in the early twentieth century so you might easily find some connections between the art explored there and the work of Andrei Bely. The reference to "St. Petersburg" is one that is certainly to be expanded. Some years ago one of my assistants, Herbert "Trey" Matteson did a large project on the mathematics of that novel, especially its dimensional implications. There are other tie-ins with Russian philosophical thought, in the work of Ouspenskii and Gurdieff for example. Higher-dimensional symbolism appears often in the writings and in the artwork coming out of Russia at this time.
The case of Dali is more complicated. His inspiration predates the nineteenth century and in fact goes back to the twelfth-thirteenth century mystic and polymath Ramon Lull, as elaborated three centuries later by a Lullian, Juan de Herera, architect of El Escorial and author of "Discurso sobre la figura cubica". Dali, another Catalonian, saw his work as representing the next step in the sequence. It is true that Dali's martyrs generally show no blood, almost a characteristic of the surrealist iconography. The exception is one of my favorite of Dali's works, entitled "The Martyrdom of Ramon Lull", where the predominant color is a marshmallow white, dramatically violated by red.
I don't quite agree that the four little cubes at the corners of the "transparent" eighth cube can be identified with the missing nails, but only because the symmetry seems wrong to me. Perhaps you can make your point more forcefully if you find comparable elements in the other crucifixion representations in Dali paintings. It is an interesting idea in any case, and I hope you will go farther in investigating the way Dali use mathematical and scientific themes in his art work. There has been a lot written about Dali, and by him for that matter, but relatively little attention has been paid to the mathematical aspects. If you are interested, I can point you in some possibly fruitful directions.