Maniacal belief that "your" race, gender, culture, religion, language, country, group, beliefs are better than everyone else's.
Which term would be more suitable: "jingoism" or "ethnocentrism"?
Can they be used interchangeably?
Neither one is really accurate, but jingoism is clearly closer.
Jingoism is an extreme patriotism, so it would only apply directly to the aspect country, then perhaps indirectly to the other aspects.
Ethnocentrism is the tendency to see ones own culture as the center, and measure everything against it. There is however nothing manical about it, rather that it's the natural starting point of viewing everything, so there is an inability to see it otherwise until you have gained perspective.
Use "ethnocentrism" to gently highlight that the subject in question is overly focused on itself. It generally means "to a fault," but not in an overly critical way.
Use "jingoism" to deliver a stronger rebuke. So it would apply to your quote above.
"mindless, gung-ho patriot," 1878, picked up from the refrain of a music hall song written by G.W. Hunt supporting aggressive British policy toward Russia at a time of international tension. ("We don't want to fight, But by Jingo! if we do, We've got the ships, we've got the men, We've got the money too.")
(Online Etymology Dictionary)