We are affected by people because man is a social animal.
The effects of peer pressure is very widespread and individual opinions cannot be freely expressed in Korea.
Expressing my opinion have to endure so many things. (I'm not sure what you mean here.)
Older people's opinions have more power than younger people's. Older people always want younger people to respect them.
If you disagree with an older person's opinion, they always say, "How dare you!"
They always say, "You will pay for this," but nothing happens.
Individual opinions should be respected; however, older people use peer pressure to be respected.
(I am not sure this is peer pressure, exactly. It seems more like generational difference. Also, the term "boomer" technically refers to a specific generation, the baby boomers. Even though colloquially, people can use it to mean "old people," it might be better to be specific in your wording.)