By Dave Seanor ARDMORE, PA. ighteen foreign nations were represented last week at the U.S. Amateur, which was won E by an Italian. Be advised: Edoardo Molinari’s victory at Merion Golf Club might become a trend on the amateur tournament circuit in America, thanks to amended Rules of Amateur Status that the U.S. Golf Association is putting into effect Jan. 1, 2006. The USGA announced Aug. 26 that, beginning next year, amateur golfers under its jurisdiction (United States and Mexico) will be allowed to accept reimbursement for expenses to play in competitions. Also to be revised are the guidelines for amateur reinstatement and penalties for accepting hole-in-one prizes.