In short why didn't they ever make any weapons out of metal? I read somewhere they did discover Metallurgy. Or it doesn't seem like it was mass produced.
Also was there a lot more breeding between Spaniards and Meso Americans. Compared to North American Natives and the Europeans that invaded North America? This seems quite evident considering Mexicans can seem pretty mix.
They had their own weapons made from obsidian or other materials that were quite effective. They did have the Tezpotli which was kind of like a copper axe, so there were metal weapons that were produced throughout Mexico.
For your second question, I think it's simply a matter of demographics. Take a look at these maps, specifically the one at 1500 AD. The population density was much higher in areas conquered by the Spanish, there were simply a lot more native people there. Therefore a lot more natives survived the plagues, so there were more natives to mix with the Spaniards. Contrast that with the density of the rest of North America on that same map. Natives and Europeans (especially the French) did mix a lot in North America, but the native population was so small that it was drowned out by European migrants.
