All great advice here Jessie. To add to what has already been said, sprinting should be part of your weekly training. The only way to get faster is to run faster. Practice Randy's technique suggestions while doing all-out sets of 100m, 200m and 400M repeats. Warm-up with some easy jogging then really hit the sprints hard. Start with 7x100m. Sprint 100m walk back to the start to recover and repeat. Each week add another rep until you're doing 10. Then start working the 7x200. It's extremely taxing work so only do it once a week.
I can't stress the strength training enough either. Once a week squat, deadlift and press heavy, 3 sets of 5 should be enough.
As far as Crossfit, if you were doing the program the PT test would not be a concern.
