Well the word sedentary mean that a person is inactive or spends a lot of time seated. So she could mean that she is "lazy" or inactive most of the time
Personal experience and a higher level of education on a subject than the other person.
The purpose of the introduction is to present the main idea
Judge Brack is a friend of Tesman and his wife, a person who goes to their house a lot. He constantly puts himself into the business and affairs of the tesman, and can even say that with ulterior motives (interest in hedda, tesman's wife). Tesman, for his age, is naive and foolish, always trying to please Hedda, he competes for a professorship, and Brack passed on information about it, to lend him a hand and help him. All this with a hidden desire, the desire to approach Hedda. Lovborg in this triangle, is Tesman's biggest competitor in the academic world. At some point in this story, it is explicit that he and Haddad had a relationship. In that case, the three of them are connected to one person, Heddad. Tesman is aware of the competition with Lovborg, but does not know anything about Judge brack. The role of each of them is 3 men in love with the same woman. Tesman is the one close to Hedda, Judge brack is the one trying to be in the middle of their relationship, and lovborg hides an old relationship with her.
