Yeah, definitely, Brunestud IS too broken.
I don't know about SHIKI, though, I think he might be a little too vulnerable, even with his regenerating ability, and he's not really worth the 6-mana cost. for a 1/1 with blood curse and death touch that needs you to sacrifice a creature to regenerate. Maybe you should make him able to create tokens? Yeah, he can become too broken with that, but you might give him an ability like 1B, Tap: Create an undead creature 1/1 token. This can only be done during your turn (to prevent him from being able to block and make a token in the end of the opponent's turn. Your call in that field, though).
About Vampiric Bite, maybe you might raise the cost a little bit and create an undead token as well if the creature is sent to the graveyard. OR you could do something else. If it goes to the graveyard, flip a coin. If heads, flip another coin. If you flip heads on the second flip, return it to play under your control and it gains the creature type Vampire. If you flip heads only in the first flip, return it to play under your control with the creature type Undead and in a weakened state (like -2/-0, -1/-1 may be too risky in case the creature has a defense of 1, but maybe you could reduce the defense to 1 and reduce the attack by or to a certain number I might be storming way too much in this one, though).
Yeah, the familiar might be too cheap, given some vampires you can have in field. Try raising her cost by 1 or 2.
As for Sacchin, for once, it's not sad for her! Anyway, it's not very easy to flip her quickly. People with vampires'll be a little wary with her, and you need quite the good combination of mana if you want to put a vampire and her on field. You need mostly black mana for vampires, and Sacchin costs 2 white mana, so you'd need quite a good combination of what you want. Anyway, it shouldn't be about teams. Instead of 'If Yumizuka Satsuki is in the same team of a vampire', it should be 'If you control a vampire. Same with Vampiric Familiar, it should be 'a vampire you control'.