Unfortunately, to many illegal deals are proceeding involving cryptocurrencies.
Don't be ridiculous. It is true that cryptocurrencies are used for illegal things but we have remember that fiat, gold and other valuable things are more common when it comes to doing anonymous, illegal payments.
Knowledge always helps people making their right choice. You are right - if Bitcoin is taught in schools, more persons will understand how it is important.
Not necessarily, I doubt that every single student will understand the purpose of cryptocurrencies' existence. There are still many people who don't know what inflation and deflation is, even though it was taught in the school. Also, I met people who actually didn't see anything wrong with printing additional money. I'm terrified how people became so naive.