The only think I find creepy is the uncle housing teenaged boys! But overall I really love the idea and I'm fine with doubling main characters. And having a wacky bunch of cast helping ships along the way! Though perhaps we can bring in more of the world. Maybe the vampire who bit him is looking for his 'kin' now or it's an XMen like school. Maybe make it as dangerous as hog warts which was a really unsafe but fun school. 

 Also, I almost think this would please you, but maybe the familiar can be in the shape of a Pokemon as well XD