Though on the technological question, I'm curious how the conflict with europe would have gone if they didn't have to deal with the slew of epidemics that resulted from first contact and killed off the majority of people there before the europeans even started looking at the mainland instead of just colonizing the Caribbean islands.

The Inca were figuring out tactics to use against the Spanish and were able to halt their advance several times, but didn't have the numbers to really push back, plus were just on the tail end of civil war that could have been caused in part by the sickness destabilizing things before the spainish even realized there was an empire there (that wasn't just their wild goose chase for a city of gold).

Not sure if the Aztecs would have turned out differently, though it probably would have been a longer war and perhaps would have gone hot before they made it to their capital and took their leader hostage. But they did awe him to the point that he thought appeasement would be a better strategy, not realizing they had no intention of leaving.