Here's some timestamps and guide to help you better:
1:55 - Found dressing room 5 key Room 5 has key to 1, 1 has key to 2, 2 has key to 3, 3 has key to 4, 4 has key to 6 Props are only in room 6 and 1, so if you're saving energy, no need to open the others 4:43 - VHS Videotape part 5:44 - Treasure part 4 The key is in the most top-right locker 7:10 - Treasure part 5 8:54 - Fixing pipelines 1 9:53 - Fixing pipelines 2 11:26 - Fixing pipelines 3