She finished her makeup in the golden building, and charmingly accompanied the Emperor in the evenings.
- 金屋 is another reference to Emperor Wu; once again the tireless Wikisource guy has put the original quote from the Book of Han up. He also points out that the 嬌 here is probably a pun on Empress Chin Jiao, who Wu wanted to build the golden house for.
In the jeweled pavilions at the end of the banquets they were drunk, and relaxed in the spring.
- I'm assuming that 罷て is intended to be read as おわりて.
Her brothers and sisters were all made governors of land.
Oh, how splendid, the thriving of the shining family!
This soon affected the hearts of the mothers and fathers of the land -- it caused them to not value giving birth to boys, but rather giving birth to girls.
The high places of Lu Palace entered the blue clouds.
- This is the Huaqing Palace, the location of the Huaqing Pools mentioned earlier in the poem.
The music of the sages fluttered on the wind and could be heard here and there.
The slow singing and the gentle dancing merged with the strings (of the instruments).
- 謾 seems to be a 仮字 for 縵.
The King watched all day but it wasn't enough.
The war drums of Yuyang began to shake the earth.
- The next set of lines alludes to the events of the An Lushan rebellion; the wikipedia article on Yang Guifei has the full story of her death; without some knowledge of the basic story this part of the poem makes little sense.
Oh! The song of rainbow skirts and feather robes.
- According to the den, this is the song that Guifei enchanted Xuanzong with. I'm a little uncertain on what 驚破 means here -- both Hiromichi's furigana and the notes to the SKT indicate that it's an expression of surprise, but the meaning of the line isn't very clear. The SKT's modern Japanese translation and Wikisource say it means the drums disrupted the dance.
The ninefold palace became covered in smoke and dust.
The large army went southwest.
- This refers to the King's troops fleeing the palace.
The jewels on the imperial flag rocked back and forth, stopping and starting.
They left the capital gate to the west and went over 100 li.
The Imperial army was not sent out, and couldn't do anything.
The curved eyebrows like a moth, died before the horse.
- A very allusive reference to Yang Guifei's execution; that's an odd simile -- I don't know if it was a poetic standard. Wikisource suggests it could be an allusion to Mount Emei, where Xuanzong was going. Guifei was strangled in a Buddhist temple, but since she was killed at Mawei (馬嵬), this may be a play on words.
Her flower hairpin fell to the ground, and no one picked it up.
(Then,) her hair ornament made from the feather of a kingfisher, her gold sparrow (pin), and her jeweled hair clasp.