Name meanings

Lou Qingwu

• Lou (surname - building is the common meaning) Qing (light) Wu (dance) - poetic and graceful  name, her parents probably hoped for her to do well in poetry as well as be graceful 

Lou Lianxin

• Lou (surname) Lian (to take pity on/to adore) Xin (heart) - LLX's name means for people to cherish her and demonstrates how much her parents adore her. 

Lou Qufeng

• Lou (surname) Qu (song) Feng (wind) - also poetic name, masculine 

Dong Mei

• Dong (winter) Mei (plum) - servants normally get boring/simple names like flowers because they're servants and not worth much. 

Ruan Zhen

• Second madam, Ruan (surname) Zhen (precious) - precious daughter, she's doted on in her family. 

Lou Xun'er 

• Lou (surname) Xun (fragrance/smell) Er (diminutive suffix/added for endearment at the end of a name) - she's the youngest daughter so she's get a little 'er' in her name but she's still got the crafty concubine genes sadly. 

Xiahou Qing

• Xiahou (surname) Qing (to raise a hand) - his name shows his ambition and desire to climb up to the highest position (emperor) 

Xiahou Rui

• Xiahou (surname) Rui (astute) - common name for princes apparently, parents were hoping that they'd be astute and far sighted as an emperor/prince

Xiahou Liuyun

• Xiahou (surname) Liu (drifting/flowing) Yun (cloud) - a floating cloud name which also shows his personality, his mother probably didn't want him to fight for the throne 

Feng Yege

• Feng (surname) Ye (night) Ge (song) - well the female lead is a dance to which he is a song. Just joking, but he has a different surname because his father-prince had a different surname but also because his lineage is a bit of a question mark

Li Miu

• Li (surname) Miu (to plot/wrong) - plotting prime ministers, who woulda thunk it

Li Jingsheng 

• Li (surname) Jing (city) Sheng (prosperous/flourishing) - he's the oldest son despite not being legitimate born so his mother was probably hoping him to have an excellent career and prospects, and possibly inherit his father's estate

Li Ziqing 

• Li (surname) Zi (children) Qing (endearment/way the emperor addressed officials) - his mother hoped that he would be a dear child because he's the only other legitimate born. He's younger than LJS so his mother, the legitimate wife, was probably feeling quite threatened by the concubine who gave birth to LJS. There's a Chinese saying that mothers can use their children to gain, which is why many concubine born try very hard and their mothers push them hard to gain affection from their husbands. 

Tang Two 

• Tang (family name) Er (two - I've used two) - subordinate names sometimes use the surname of their master and then numbers as their name. This isn't his real name, but the name he takes on as a subordinate which becomes his name under his master. 

*

I'm bored and should be translating so this is just some really useless trivia. They're just little hints that are dropped by the author that don't come out in translation because readers don't know which words were used by the author. Or the curtains are blue so take it with a grain of salt.