President Clinton today called for sweeping changes in the proposed national tobacco settlement, including industry penalties of up to a $1.50 per pack if teen-age smoking fails to fall sharply over 10 years. In making his first detailed comment on the $368-billion tobacco settlement reached in June, Clinton effectively refused to endorse the agreement, outlining so many changes that it was certain to serve as little more than a starting point for any legislation that Congress may ultimately fashion. Minnesota's lawsuit against the industry is set to go to court in January. State Attorney General Skip Humphrey, who has been highly critical of the tobacco companies and the settlement, says the original settlement is dead. It's not, he says, just a bargaining tactic by the President.