Its gonna be worse with Carlist Argentina considering how the Spanish Royal family was held captive by Napoleon.
Its likely going to be a buffer state. Though it does have a lot of resources, so by the time of the later 19th Century when oil is discovered, it can make a huge killing off it. With its access to the Missippi River basin which is one of the most fertile and navigable waterways in the world, Louisana would likely be a major agrarian center. This could lead to an eventual population explosion. You could also see French investment spread there which would also likely boos industrialization as well.
As for demographics, it would likely be a melting pot of the Anglophone, Francophone, and Hispanic world.
True. Though I wonder if China might modernize somewhat more, being worried about Japan.