Discourse analysis helps us develop language and consequently must be a strong influence on linguistic knowledge.

Many languages require complex analysis to understand, others take a more simplistic approach implying strict grammatical rules.

Yes, as also written by Barry Turner, DA does shape our linguistic knowledge because it fixes a linguistic framework for the writer. This linguistic framework draws a boundary line for the writer to use specific grammatical structures, lexical choices, and cohesive devices according to the field of discourse. A writer's tone can be different from genre to genre, and from topic to topic; the tone can be formal, informal, subjective, objective, critical, persuasive, etc.

I agree. Discourse analysis and conversation analysis help understand how language is structured, managed and perceived. It allows us to note patterns and to understand pragmatics (i.e., the real meaning or intention of words / requests / statements, etc.). For example, "you know" can be used as a sharedness marker and/or as a form of hedging (or negative politeness) to soften the impact of an utterance. DA and CA help us unveil such nuances. Additionally, the ways turns are taken are also important. A turn taker can even be a non-word (such as "erm"), as well as a response token ("uh-uh") which convenys interest in an interactant's words.

I would argue that carrying out a Discourse Analysis on a specific text genre could, as a form of by-product, improve your knowledge about language (as "linguistic knowledge"), but not necessarily your language of knowledge (as "linguistic knowledge"), since you already have the required language skills to produce texts in that genre. Of course, if you are learning this language as an L2, you could also improve your knowledge of that language. Also, maybe for very specialized L1 text genres that use technical vocabulary.

Darwin said "half art, half instinct.

See Attached

Discourse analysis shapes our linguistic knowledge at least for two reasons. First, discourse analysis helps us differentiate a text from merely a group of words, phrases, clauses, or sentences using the concept of textuality (De Beaugrande and Dressler 1981). Second, It makes our knowledge about the relationship between language forms and functions more comprehensive because discourse analysis teaches us how to use grammatically correct and contextually appropriate language. Discourse analysis also guides us in comprehending text as intended by the text producer. Enhancing our knowledge of discourse analysis helps us increase our understanding of both language usage and use.

DA gives us a linguistic in depth into a text, one is able to get down to the context of issues and foreground the understand of a subject matter from a basic arrangement of words and word choices.