1)you could say that the families longstanding feud was the reason the lovers couldnt be together in the first place and acted as a catalyst to all the disastrous events that followed. If the families had put their feud aside the couple could have married and so the whole thing of juliet faking her death and then romeo killing himself blah blah wouldnt have happened.
2) both juliets parents were incredibly overbearing and her dad was pushing her to marry paris so naturally she couldn't tell him about her wanting to marry romeo. but juliets mother was always distant from her daughter and so if their relationship wasn't as strained perhaps juliet could have discussed her desire to marry romeo with her mother and the families could have possible come to some agreement to allow the lovers to be together and so they wouldnt have died trying to elope
