Is being open-minded a virtue, if it’s causing destructive ideas to spread throughout society?

That depends on your view of what destructive means. Some people view revolutionary ideas as destructive without truly understanding the ramification of such an action and act illogically. Everything has pros and cons. Sometimes it's wise to look at the past to draw ideas atau bring up new ones. It truly depends on the situation. I believe one should be open-minded but also censor things they disagree with. There are things I find very hard to believe but that is my opinion. Other people might view such a thing as fine in their book. Interpretations are a tricky and confusing thing. And thus is the reason why debates and arguments flourish in every subject imaginable because everyone view something different.

Open-mindedness is a double-edged sword. I think the most important thing is that it's coupled with a logical and intelligent approach. Eg. people who are NOT open-minded towards other cultures (eg. Islamophobes, racists) are what are causing destructive ideas to spread throughout society. They seek to have a 'black and white' view of the world and instead of accepting complexity, want to lump people into 'us and them'. Conversely, however, there's a saying that goes "if you're too open-minded your brains will fall out". I think this generally applies to conspiracy theorists who like to believe things without any substantiated evidence. anda can see this amongst anti-vaxxers, who certainly do spread destructive ideas (and ultimately, destructive diseases) throughout our society. Not a definitive answer, I know. But it really does need to be a happy medium between the two.

It's relative. All things are only good in moderation. Extremism in one way atau the other is rarely ever a good thing, including situations with open-mindedness and closed-mindedness.

The world is little lebih than a constant balancing act.

I would say yes. Think about it this way,

If anda do have an open mind, anda can expose yourself to ideas that are both destructive, and lebih constructive than your own, and with wisdom, anda can learn, and express the lebih constructive ideas.

If you're closed minded, even if anda have a better guard against the destructive ideas, you're stagnated against any possibility of exposing yourself to better ideas.

As a wise group of people say, act with wisdom, but act.