If you can get him into the Feb. 8 ACT, that would be a really good thing. In part because it probably won't interfere with any baseball activity (the next ACT is April 4, the SAT dates are March 14 and May 2), in part because HA coaches may not take him seriously without a score. He can take these tests more than once with no penalty at all, but you want him to have a score going into the summer; PSAT is not going to tell them much.
60-time is the major measurable for shortstops, along with EV. Better know that too, it will give you a better idea of what kinds of schools to target. You can measure it fairly easily on a football field (assuming it gets above freezing in the middle of the country!)
We never asked for pre-reads; the coaches asked my son to send information for a pre-read when they were interested.