1. "Kids, don't worry if you fail. Most people fail, so you won't be alone" sounds like pretty much the most sensible thing anyone could say to kids anywhere.
2. I believe you dont know Bielsa and have little idea of what he has learnt or not.
Could just do like Sir Alex otherwise, speak his native language which no one understands and then everyone is just going to assume he said brilliant things.
Ye. Probably some anxiety thing, I think he likes to be a perfectionist so doesnt want to be caught with non-perfect English.
Quite likely the man has some sort of diagnosis.