Catholics would definitely go there, free land is free land
Yes, they could. I just don't think they will. Free land is good, but not when it comes along with a constant war with violent natives and raids by the Spanish. They can easily expand to the rest of Brazil. Without having the problem of very violent tribes and, worst of all, the Spanish. The barbarian wars in the 17th century demonstrate this. Cattle production in the rest of Brazil is possible and safer (Yes, the land is not that good, but on the other hand they have the colonial government close by to protect them). The northeast and southeast can produce cattle and sheep/goats/pork without any major problems. Weck is even easier being close to the colony's large urban centers. The south was in this era a free for all. You survived alone without government support. Which will not be advantageous for the Catholics who are the core of the colonial government. They will go south only after the gold boom ends. Before that, there aren't many advantages. It will take at least a century if not more for the Huguenots to stabilize the region. By stabilizing, I mean minimally functional, not that it will be ok.
, especially given many nobles and non nobles under the leadership of the Guise family are financing Catholics to move to Brazil in order to "steam the tide of heretical protestants"
They can finance all they want, Catholic immigration will actually occur in large scale when gold is discovered. Before that, even if Catholic migration is large for the era, it will be concentrated in areas vital to France. Cash crop regions. It is not economically interesting to send hundreds of thousands of Catholics to die in the south simply to try to equalize the number with the Calvinists.
Plus it's also worth mentioning that so far most Huguenots are heading into the Northeast as well given it's the rich region and they can put many of their skills to good use(given many of them were/are nobility and merchants) to make a good profit.
Yes to urban centers. Probably working in textile industries, being doctor, creating banks and similar things. These will be the most "liberal" Huguenots.
, there would be the adventurers ones willing to go further South, especially given the Bandeirantes are already doing their duty
The bandeirantes built small forts and advanced after the natives. They weren't there to create communities. They went to a place, enslaved all the natives, set up a fort( after that they either advanced or returned home.). They returned to São Paulo (and sell the slaves), after that they made a new expedition to see if they had precious materials (or they did this during the first expedition).
Prepare a new expedition further away, and the cycle continues until they are stopped or get stuck in a very difficult geographical barrier. Always looking for slaves or riches.
Plus, large cattle ranching was always the major economic thing of the South in OTL as the Pampas are perfect for that.
The south in this era was not economically important, has no mineral wealth, and is on the border of Spanish territory. It's literally the worst position. That's why Calvinists are being sent there. Imagine that it is basically Siberia in the French colony (It's the corner that no one wants). They are being sent to a region that can only produce subsistence agriculture (which the metropolis knows about at least) and cattle. Which is far from the French centers of power so in theory they won't be able to poison the loyal subjects of France (aka Catholics).
Any investment that France makes in this region will not be due to agriculture or livestock, but rather due to the Plata Basin allowing access to Bolivia. Allowing France to take part of the silver produced there illegally. Everything else about this region in this era is meh. Agriculture and livestock is good, but they don't need it at the moment. And if they need to, they can buy from the northeast of the colony. The economic and cultural center of the colony.
Now there is a way to have a Catholic presence in the region. Through a French trading company whose purpose is to control the Plata basin to access the Bolivian mines. Something similar to the French beaver company in North America. The company wanting access to Bolivia, beelines to the important fort-cities in the region. Destroying or conquering them. Ignoring the rest (as it is something secondary). These important cities would be controlled by Catholics. But the number will not be large enough to match the Calvinists. It will basically be an urban minority loyal to the crown/colonial government surrounded by a rural population that is not very loyal. Which is basically what happens in OTL (both with Portuguese and Spanish).
jerky production will shift south given the region is great for it
On the scale you're talking about, it will only happen in the 18th or 19th century. Before that, it will be sold to the colony, and what's left (If there's any left, it will be sold to whoever buys it at the port). The demand needed for true mass production of jerky requires a really large colonial population. The south, until the colony has this population boom, will have an economy that is a mix of cattle production, subsistence agriculture and trade among Calvinists. The south will not compare to the wealth exposed in the northeast and southeast. It's going to be the meh region. The region will only really start to shine in the 18th and foward.
and like OTL we will see the big owners of ranches show up and enlarge the Catholic presence, which would make the Huguenots go further south as well as into the interior.
If the big catholic ranchers show up they will end up dead. ITTL south is not the same as OTL in population. If Calvinist immigration is very low to the south (that's 200 thousand, 10% of all French Calvinists) in 1 century they will be something around 300 thousand minimum (low birth rate and high mortality, which will not occur in the region due to the climate being tempered). This is if immigration is small. By 1700 they could easily be 500 thousand if not more (OTL Brazil in this era had 300 thousand).
The region will be Calvinist, but that's not a bad thing. The colony, due to its issue of tolerance, will have different regions. This is the advantage and disadvantage of religious freedom. It attracts a lot of immigration from religious minorities. I would say that the population of the colony will be between otl new granada (1.5 million) and new spain (4.5 million) in 1700. La Plata in OTL in 1700 had 450 thousand against Brazil with 300 thousand (Weck seeing TTL population of la plata, I will say that ITTL the population of that region could easily be 1 million if not more.).The otl Brazil population boom comes with gold.
meanwhile Spain is having it's first signs of decadence but they're still far from the mess of Carlos's II time, so it isn't like France will have a easy time trying to paint the map blue, at least for now.
I tend to think that we are going to have several wars on the scale of the OTL thirty years war.