Should I always put “the” in front of “Dutch”?
No, you do not always have to put "the" in front of "Dutch," however, it sounds more natural in English to put "the" in front of "Dutch." If you do not say "the Dutch," and just say "Dutch," it sounds like you are talking about the language instead of the people. Instead, you would have to be specific: "Dutch people." Either way is fine to use, but the more natural way would be "The Dutch."