About #3, there's a problem when the message is worded exactly the same way for "we didn't have time to test masks yet" and "we have evidence that those medicines are harmful, but we won't seek confirmation because we are looking for helpful ones instead".

But that is of secondary importance, because early in the pandemics a lot of health organizations made it very clear that not using masks should be the policy. It wasn't a communication problem, they were just lying to people to get to a goal (masks not disappearing from the market, a good goal). That's wrong on many different ways.