I was also under the impression it was aimed at the shonen demographic but some episodes make me ponder otherwise. The 'bloodyness' comes in a bit later, shortly after the tower of Heaven Arc.
*Resisting the urge to tell you how awesome it get's as it progresses!*
As far as bad guy's go, I adore Hisoka's character he is always plotting something people are like toys to him. Illumi at this point in the anime is a close second. Finally Merum (you will come to meet later) is possibly the best bad guy in an anime ever, he is right at the top above Hisoka.






