With the cover page, I mostly mean that it doesn't really clearly lay out that when you say "Crew," you're specifically referring to the new Archetypes you've included! There's an explainer on the outside-middle panel that gives sort of the context I'm talking about, but it gets muddy since "crew" is used pretty interchangeably in a lot of MoSh stuff as "party" or "PCs," whereas here it's kind of a bespoke "Mythhunters Crew Archetypes" thing.
Gotcha! Makes sense with the Stereotypes, although I feel like there's probably a more accurate name out there. I don't even think there's anything wrong with fully saying "additional Trauma Response" or something. I know the core PSG allows other classes to "gain the Marine trauma response" if they undertake military training - its ambiguous whether it means replace, but I think it's justifiable that the game is meant to allow you to stack multiples. Certainly doesn't break if you do!