Sorry, but I did not miss her point at all, I just thought it was poorly argued and fairly tenuous. I pretty strongly agreed with the other guest that Sully first and foremost represents a universal desire to explore, learn and discover new things: be they places, cultures or philosophies. I also agree that deep down most people want to be a hero, to do great things and be someone people admire. I think that's also pretty universal. I see that the choice of the white guy to be that hero is what's at the center of this argument. Call me cynical, but I think that's just what the studio and Cameron think will get the most butts in the seats.
Overall, I just think you can show a white person coming to respect another culture (even ones that specifically are or represent peoples that were previously/currently conquered, enslaved, embattled, etc.) without ascribing it to white guilt. I just think it's much more about ideas than race.
That said, I really like your idea for how the story could have played out differently.