The 12 most popular superstitions at the game of craps are adhered to or believed by most craps players -- so if you want to play the game and not be thought a craps barbarian, you should know them. Keep in mind that individuals add their own superstitions, too, so you might hear someone yelling some incoherent thing at the table which, to him, will ward off the coming of the ominous 7 -- or bring it on, if he is a darkside player.
Late bets thrown onto the layout or to the stickman once the shooter has been passed the dice will bring out the seven.
No, these bets will only anger the shooter and everyone else at the table. Controlled shooters could lose their concentration in these cases, so for them, the late bets can be a distraction. You don't want to be distracted if you are a controlled shooter. Also, throwing late bets out while the shooter has the dice is terrible table manners. Indeed, some casinos will tell their box people and dealers to reject late bets while scolding the late bettor about when bets are accepted.