Inspiration: Uncle Scrooge (who is Scottish) and golf--the perfect combo. Add some characters from Greek myth and we're off! You've taken these three completely different games and meshed them together quite well.
Usability: Like the cherished modules of old, this isn't a "sit down and play it while you read it" kind of adventure. The room descriptions aren't super-lengthy, but they are dense with info and some of it is buried (like the three all-important ferryman's coins). This is the kind of adventure I would need to read a week ahead of time and make notes along the way so I don't get lost while running it. But it's doable. And the overall layout is great: one page for each section--including the map, so there's no flipping back and forth.
Vibes: Some great NPCs in here. MacDuque the caretaker, Par Al Ba-Tros the jovial djinni, the owlbear librarian... Lots of stuff to interact with as well. And it's a bit goofy, just like my favorite 8-bit video games of the '80s. Well done.