Should it not be "Ви вірите в ці забобони?". My understanding is that "в" comes after a vowel and not "у"
Can забобони not also be predjudices?
Prejudice is most commonly translated as "упередження"
Google translate gives "foreboding" as the first suggested translation for "забобона", although I agree that in English "superstition" is more widely used than "foreboding"
IMHO foreboding is more like передчуття поганого