I suggest that when looking at the "relationship" between Cora and the Huron chief Magua we should consider what was happening in America at the time the text was written in terms of race relations. After all, the narrative contains an undercurrent of failed interracial relationships ( consider Cora's mother, for instance, who is non-white). Antebellum America was in a fierce grip of miscegenation phobia, or a fear of interracial sexual relations. This anxiety actually continued to exist in codified form in Virginia, for example, until the case of Loving vs. Virgina reached the Supreme Court in the 1960's.
When we look at Coopers text then we should ask how he negotiates the fate of that relationship. It is certainly not a love story, since Cora is violently abducted to his "wigwam". Magua is portrayed as rather animalistic, driven by pure sexual lust and primal masculinity. Cora, in contrast to her virginal, blond sister Alice, is sassy and quite often questions Major Heyward. Since the text itself traces the construction of the American empire ( it takes place during the French-Indian War), an apt reading should consider what place the text accords Cora and Magua in the future republic. Along with countless Indians, they die. It seems that the text suggests that America has no place for Native Americans and interracial people like Cora. They are a threatening presence.
Historically speaking this is congruent with what was happening in the US at the time, since the the question of what to do with Native Americans became a prominent issue that lead to the Trail of Tears where thousands of Native Americans perished under the guise of resettlement in the west.
The best lesson? Love comes not where it is expected, and can disrupt all choices and plans. To have love and/or success, you must act, and at times that action would mean breaking social mores and the expectations of your group (tribe, nation, etc.).