This TL is awesome, so good it actually cause me to learn a lot of things, or think about them differently.
Between the great powers of the continent (BTW how do the various cultures refers to their own continent?) I think tha Maya are the most vulnerable to fragmentation and infiltrations by the europeans (as the Spanish are doing).
The success of Incan expeditions will cause them to give up on the Northern continent? When you can choose between Malacca and "San Francisco"....
Paititi will become a superpower if they manage to grow a least some of those tree they got in Indonesia (and what they can't grow they can get directly from India, so they can split routes with Qusqu: Far East to the latter, India to the former).
What are gonna be the effect of spice prices skyrocketing due to Incan presence in Malacca for Europe?