I regularly review what I bought, and what was good or bad shopping for me.

good / bad + shopping sounds unnatural. good / bad + purchases is a more natural option.

By this habit, I can distinguish if the things I want are necessary or not to a certain extent.

deciding if the things you buy are necessary is a likely result of "distinguishing" them, so use "if" sentence to show this relationship.

I think books are an investment that never loswastes my money.

"lose" gives the feeling that you lost your money somewhere, but "waste" gives this feeling of whether the purchase was worth it or not.

Great books have become my irreplaceable treasure.

treasuring your books started in the past and continues, so use "have + become" (present perfect tense)

Even though a book is trashy, the book would be a part of my knowledge, and criticizing the content is also profitable tofor deepening my thought.

"criticizing the content" of the book is a thing / object and it's purpose is for "deepening" your thoughts.
- When describing an object / thing's purpose you should use "for" ("for" + verb-ing)

"to" is used if you are describing a person's purpose. ("She sat down to read")

You could also write:
"I criticize the content to deepen my thought" because the subject of this sentence is a person but "criticizing the content" is the subject in your original sentence.

However, I try to avoid poor quality books toby researching in advance or to reading a little in a bookstore before buying.

The reason you "research in advance" and "reading a little in the bookstore" is to avoid "buying poor quality books." To show this relationship you should use "by + - ing verb"
e.g.
"I stay healthy by running everyday"