In the context, this conversion happens in ancient China, so the language here is slightly more concise than modern Chinese, so '如何出名' here actually means the same as '如何（个）出名（法）', and it means 'in ...
狗尾巴草 is a kind of weed against which peasants need to fight all the time, and it is famous for its strong vitality. So peasants and poets see 狗尾巴草 as a tough enemy. For a long time, 狗尾巴草 is called 莠 ...
We can take the whole phrase to mean a sin growing from the bottom of his heart.
灰暗的狗尾巴草 just gives us a bad feeling/impression about his mind and here is metaphorically representing a (...
Here 枝 is not a classifier, or a measure word in your terminology.
折枝 (break/snap + branch) is a type of Chinese paintings. If I remember correctly, it first appeared as a type in Tang Dynasty and got ...
行文至此: At the time of writing, Thus far,
行文：Probably a reference to:
A Chinese calligraphy style of using the brush,
refers to the way of moving the tip of the brush ...
楣 is seemingly short for 倒楣 in this context
do something to bring honour to one's family.
refers to offspring become famous, create honour and glory for ancestors and clan