The solution to information being harmful out of context is not to withhold the information, but to provide the context. Teach people about biases, and that they need to inspect arguments they like for biases as well as arguments they don't like.

Withholding the information is also a solution. It you can construct a better one for a given situation is a separate issue.

Also, a person still needs to hold unjustified opinions on every subject, that's how the decisions are bootstrapped, but voicing these opinions is usually of no use to everyone else.

I don't understand the point you are making here, or the relevance of the link. What do you mean by "how the decisions are bootstrapped"? Perhaps an example would help illustrate what you are talking about.

I'm talking about priors, or what passes for them at the first step of plausibility elicitation, when you consult your gut feeling on a single question of fact. Even when you decide to seek out the additional info on a decision, you need to start from sufficient expectation in the discovered information improving your decisions. Maybe you are already convinced that Astrology is bunk, and don't need to research the Encyclopedia of Astrology in Twelve Volumes to improve the precision of your conclusion. The decisions like this are done often and without conscious notice, in fact they may determine what does receive conscious attention.