Does hearing an opposing view point actually cause harm?

No it does not. It MIGHT actually pry open closed mind if the person hearing it will actually show the MATURITY to consider it instead of just allowing the person to voice their opinion and later on blow it off without THINKING ABOUT IT just because their delicate sensibilities are too fragile to accept the fact that they themselves might actually be WRONG.

Does the opposing view point include bombing the opponent you could probably hear that.

If "harm" includes possibly discovering that you were actually wrong then I suppose it does.

Its possible. While most would agree hearing an opposing point of view would motivate the listener to consider alternative possibilities. But considering the ego, and the pride of an individual, hearing an opposing point of view can make an individual angry, and thus potentially cause harm.

No. Just another opinion. (they could be right)

Peace.

Can cause an individual cognitive dissonance. Not really harmful but not pleasing.

Here is the definition: "the state of having inconsistent thoughts, beliefs, or attitudes, especially as relating to behavioral decisions and attitude change."

there are actually teaching philosophies in primary schools that believe this...yes....

Only if your own viewpoints are so weakly held that they won't withstand being challenged.

My liberal friends tell me words are weapons, and cut just as easily as a knife and can be just as deadly. That's why liberals have to be in charge of what you can say, so that you won't hurt anyone.

It's the opposite, hearing various points of view is good for everyone. Hiding from opposing points of view leads to paranoia and bigotry. It can be done politely though. Discussing different points of view doesn't have to involve constant insults.