A Vampire spell is a spell with the creature type Vampire on its type line, regardless of whether the word "Vampire" is in its name.

If an effect refers to a Blood token, it means any artifact token with the subtype Blood, even if it has gained other subtypes.

You can't sacrifice a Blood token to pay multiple costs.

Some triggered abilities trigger "whenever you sacrifice a Blood token." These abilities trigger regardless of why you sacrificed that Blood token.