NATO doesn't recognize double triangle flag countries?
NATO is a members only alliance of several countries. Nepal has a double triangle flag. Nepal has not been recognized as a member of NATO.
The answer is yes.

Is there a full Neptunian orbit between the first two burials of women in the Panthéon?
In 1907, Sophie Berthelot is the first woman to be interred in the Panthéon. In 1995, Marie Curie is the second woman to be interred there. Neptune takes 165 years to go around the sun.
The answer is no.

Could a delicious recipe be made with The Onion?
Despite its name, The Onion is not a food, but rather an organization. It is not possible to eat a business organization.
The answer is no.

Do all crustaceans live in the ocean?
The woodlice family of crustaceans is terrestrial. There are also many crustacean species living in fresh water rivers and lakes.
The answer is no.