there can be some variations. I’ve also seen a lot of “chest hits your buddies fist”, which for long armed guys is sometimes more than 90, for shorter arms it can be less. Also depends on the grader to a degree, and also what PST. Contracting PSTs and “day 2” PSTs are very strict. Practice ones can be less so. And studs tend to get less attention, the weaker guys take most of the attention. In any event, training for 90 or a little past will only help if someone isn’t being as strict.
Swim is all practice. More time in the pool is your friend. I would do an easy 500 warm up, rest a minute or two, do a timed 500, and then form work for another 500. That’s a mile. Do that a couple of times a week.
Pullups, as I’ve said, I’m a huge Armstrong Pull-up Program fan to get to 15+. Then switch to weighted 2 or 3 times a week.