1) Are you used Bitcoin to buy illegal staff

2) which better to buy legal things Bitcoin or Normal Bank system (PP,payeer,cash ,.............)
1/ Define "illegal". What is legal in one country may be illegal in another. And some of the items which are not
de jure legal may be
de facto legal.
2/ It is up to you. If you get good deals with Bitcoin payments, then go with it.
Definitely we didn't have exact point on how we spent bitcoin for our daily lives, and partly that's right having freedom of decentralized bitcoin depends on how we finally deal with it in proper manners. In a certain country which bitcoin always in focus of, there's no circumstances when a specific transaction wasn't actually transparent to the authorities or a government body so no strict implementations for whatsoever dark uses. As long as it remains smoothly processed behind separation from fiat economy, I guess that's fairly successful to use regardless on how good or bad it is.