Alternate pre-Colombian contacts are fascinating, so I understand your interest, but I think your posts share a couple of problems that might be preventing the debate you're hoping for.
1. You can't just post a youtube video and expect it to pitch the scenario for you. Most people check in on the site on their phones during the course of the day and don't have the time to watch a... God, almost seventeen minutes of youtube.
2. Also, It's worth pointing out that if they do have the time, watching a random person talk for seventeen minutes about this scenario is probably not want they want to spend it on. This is a discussion board- written text comes first.
3. Your scenarios keep skipping to the end, as it were- how will the indigenous peoples ('Natives' is a word you should be careful about using) deal with the Europeans if they're sufficiently stocked with iron and immunity et cetera. Except that's skipping potentially centuries of divergent history. Why will European contact happen on schedule or in a recognizable manner if Eurasia and Africa have already gone through sweeping economic and political changes?
4. Also, while we're at it- your posts are asking two very different questions. 'What if the Chola Empire or the Vikings'... well, either one of those require completely different examinations. Similarly, the Malinese or "a Chinese Empire" don't even share a trade network. Why look at them together?
5. Lastly, with the possible exception of Viking contact, all of these questions suppose sweeping changes to the colonising cultures that can't be swept aside. For the Ming or the Chola to colonise the Americas we have to imagine a fundamental reworking of the trade and political networks of Eurasia. Maybe look at the changes to the Chinese and the Indians before we imagine how they affect the Americas.
6. Final point: I am personally incredibly dubious of the idea that there was some hypothetical great power that could embark in mass colonisation without genocide. The historical record is pretty clear that the killing and enslaving happens and then the society works out an intellectual framework to justify it.