If allowed to develop for 500 more years without European meddling,

>>2321233
They would have needed much much longer than 500 years. IIRC they only just entered the Bronze age upon European arrival.

>>2321233
None

>>2321233
some native peoples were only conquered when the machine gun appeared, I don´t think the incas or mayas could have expanded much

>>2321233
Maya were not on their way out. They were actually beginning to experience a sort of renaissance to the Classical period after the Leage of Mayapan fell apart. The Aztecs would have to contend with the Purepecha and the Tlaxcaltecs which they could have done. The Purepecha would be harder and would likely turn into a war simialr to the Punic wars of Rome and Carthage. The Inca assuming they settle their civil war would recover and probably continue expanding. They would have trouble with the Mapuche. They'd probably start colonizing the Pacific coast of lower Central America. The Nahuas and Aztecs were already colonizing parts of upper central america. Eventually they would have had more increased interaction, especially if the Aztecs conquered the Purepecha and got access to their ports which had contacts with Andeans. I imagine the Aztec and Inca would be like Rome and Han China. Having limited relations but aware of each others existence.

With increased trade between the north and south in contrast to the east and west of eurasia, ideas and technology and probably religions would be in flux. This would promote newer technologies and ideas. Inca bronze would probably be more widespread in Mesoamerica and Mesoamerican codices would probably start arriving in the Andes influencing them. This would periodically be interrupted by droughts and instability. The Maya would increase its trade with the Caribbean and the gulf of Mexico. In general I think interactions between north and south america would increase as it was shown to be increasing more in the final years before the Spaniards came. Emerging would probably be notable explorers, so ship building might become more advanced aside from the reed boats the andeans used and wooden canoes of mesoamerica (some which were historically big enough to hold dozens, probably 20-40 people according to Columbus).