Check out the book The End of the World is Just the Beginning by Peter Zeihan. He uses public data to examine breakdowns in trade, climate, and demographics and which countries stand to lose or gain based on their history of policy making.
In the big picture, more conflict, more human rights violations, more fascism. While crisis brings people together locally, when the going gets real tough for everyone, tribalism and us vs. them will inevitably rear its ugly head.
Tens of millions of people needing to migrate because the areas they live now will become literally uninhabitable (as in not "it'll be a little uncomfortable and hot" but "you will die if you stay there") will be an absolute horrorshow. Genocide, really—I'm fully expecting criminalization of all rescue orgs, "sink on sight" orders for migrant boats and absolute ban on saving any migrant castaway on the Mediterranean.
Your last two predictions are far-fetched in their cynicism. If it gets to that point, the laws will be irrelevant anyway. As it stands today, the migrants are far from the dregs of their own societies. With a bit more enforcement and coordination the boats would stop coming. Presumably the numbers will rise but the genuinely desperate climate refugees of the future will always be going to the first nearby country where they are safe, not halfway round the world to the place with the best economic prospects. Not claiming that any of this is fair, but then the tribalism that you mention is also what makes the cohesion of our societies. People will always resist being overrun from the outside, and that will not make them fascist.
Tough to say, crisis sometimes brings out the best in people. But my gut says this is going to go very badly. Farming is based on steady, long term patterns many of which are being disrupted by climate change while traditional sources of water are becoming more scarce.
America went from the richest country in the world to slightly less rich but still the richest, freaked out and elected donald trump. How will poor, occasionally heavily armed, nations react to famine?
Countries with the raw materials needed to make modern batteries are about to need some freedom. This is actually scary, because a lot of those minerals are in Africa, and China has a pretty large investment in Africa, already.
If I do REALLY well I've got about another 45 years to live. 35 is probably a more likely achievable goal. I feel very sure I will witness wars for oil (explicit wars for oil, not what we have now) and for water in my lifetime. I don't think it bodes well for relations between nations OR global politics.