re: How many games would an elite high school all star team win in the MLB?

Zero. Baseball might be the most random sport there is but it's also the sport with the biggest leap between their high school and professional leagues. It's pretty rare for a 21 or 22 year old to be a top player in MLB but you see players from that age group play at a star caliber level all the time in basketball, football, hockey, soccer, tennis, etc.... The only sport that might have a steeper learning curve than baseball is golf. It's just really hard for youngsters to do well in baseball.