Can I do more before going into the goddess statue Leon A?

[Okay]

I've gotten 3 medallions and found out the passage closes behind you when you enter. I reloaded the save but I cant find anywhere else to solve any more of the puzzles or locks. Are any of these solvable before I go in:

- STARS PC / Locked room
- Library shelf jack
- Diamond door lock linen room
- Waiting room safe
- Crank handle slot
- Second key for Lockers Terminal
- Records room heart/club door
- 3F Dial lock West side

I want to do as much as I can on my first playthrough. I also read about Mr. X patrolling but I haven't seen him yet, idk if I'm supposed to. I don't need a walkthrough to solve them if I can do it, I just want to know whether its a waste of time to keep searching or not.

[Hex: Cheeks🍑Looper]

Without saying too much of how you can solve everything/certain things, you will return to the police station later on after progressing.