밑줄 친 부분만 모르겠어요! 앞뒤문장들은 문맥을 위해서T-T

1. ‘성차별’을 함의하는 단어들에 대한 글인데요.

이 한 문장이 이해가 안 갑니다.

Male and female actors usually play different kinds of roles, so it's useful for people in show business to make this distinction. If "actress" saves them from having to use "female actor", why not use it?

2.'불평/불만‘ 하는 사람에 대한 글이에요

If you're the employee that complains about clients or the workload or the commute or the manager, this will definitely pose a problem with your employer and co-workers. Just as damaging can be your tendency to arrive late and leave early.

이건 해석이 어떻게 되는 건가요?

3.A manager who senses that negativity is permeating the workplace will likely address the issue, which could hurt the naysayer's salary increase, bonus, or chances for promotion.

이 문장은 이 밑줄 친 부분만 잘 모르겠습니다.

4.유투브에 관한 글입니다.

Youtube put the right technology out there to meet a need, but it did so much more than that.

이 밑줄 친 부분 해석이 어떻게 되나요?

두리뭉실하게는 이해가 되는지라.... 직역 해주실수 있으면 부탁드리겠습니다 ㅠ_ㅠ!!