Research approach for PhD thesis in Taoism: top down vs. bottom up
In general, I agree with JeffE. Both top down and bottom up.

In the case of Taoism, there is more - how proficient is your Chinese?

You said pursue lifetime in Taoist research. I am not sure you can do that without knowledge in Chinese language equivalent to at least masters degree in Chinese.

Taoism is rooted from Laozi's original text Daodejing. Reference Taoism. Most native Chinese speakers do not understand that text. If you want to conduct life time research in Taoism, that book is a must read and must understand. Without fully understanding that text, you are at best a second class researcher in Taoism.

I am a native Chinese speaker. How much do I understand the text? Less than 5%. If I spend 20 years or more on it, I might be able to understand 80% of it. Actually, I am bluffing. Some people contribute his whole life in it and then claimed that he only understood less than half.