1. Domain specific and precise language in informative/ explanatory writing makes you reliable. It makes you look confident in what you're talking about. It makes your writing clearer, easier to understand, and specific because you aren't being generic. It also gives the writing a more formal tone.
2. In-text citations are important to informative/explanatory writing because they add information from outside sources. The text seems more credible and reliable if the author uses other sources and citations. Using reliable sources helps support your statement and makes the reading for interesting. It backs up your claims while giving credit to your sources.