(Fair Labor Standards Act)

I know this is a long shot but thought someone here might be able to answer a few questions about exempt employees on salary - NOT hourly employees. Or, can you possibly point me in the right direction? I don't know how much of this can be "per the employer" and how much is covered federally or at a state level.

Let's say a person is out on Monday, but then works a total of 52 hours on Tuesday-Friday. Can the employer force them to use a PTO day for that Monday?

Let's say a person works 80 hours one week, and then the next week they only work 32 hours. Can the employer force them to use a PTO day OR dock their pay 8 hours that week?

Let's say a person has a doctor's appointment and comes in 1.5 hours late one day, but still puts in 40 hours that week. Can the employer force them to use 4 hours of their PTO because they only do half or full days' worth of PTO?

Let's say there's an unpaid holiday and the office is closed, but everyone has the choice of whether or not they work that day - if the exempt, salaried employee does not work that day but works the rest of the week (32 hours) can the employer force them to use a PTO day OR dock their pay 8 hours that week? What about if they put in 40 hours for the rest of the week? What about 60?