Yes that is nature of gambling one day we are in profit but other day we had nothing, i am agreed with you on this point because we can't take gambling as serious business for daily earning.
Correct. There no rules but only luck. The machinery of blackjack is calibrated from the owner with percentage of wining for the players and for the owner. This rapport is normally 80% for the owner and 20% for the players. In my country are limits per this rapport which protect the players. But normally the actual tendency here is to make difficult the existence of casinos.