1) How do people think that bitcoin is actually anonymous? You would have to buy them with your debit card/credit card in which banks have your information... why would you think that this stuff is actually anonymous and could be used in such a way?
You don't have to buy them with your bank details. Meet someone face to face and give them cash.
3) If it is a currency that can be used in a sort of anonymous way, then how can governments regulate it in a way to make sure that people aren't funding bad organizations like ISIS and drug lords? "Harpua" has told me about what silk road was and the way the darknet markets work, but how can this be prevented?
They can't ultimately just like they cant stop them using cash.