To your first point, if this goes the way it's looking and Chauvin gets anything less than 25+ under a first degree, there will be a chimpening. But imo that's not even the real danger, the real danger will be when either the glowies or some dipshit autist decide to amp things up by doing counter "protests" which will end in bodies on the ground. Then we will start to see some nasty shit that might actually eclipse '92. It's just been boiling over for too long, and with too little release on the valve. Everyone feels entitled and most people seem to be firmly planted on one side or another. I haven't met many people who will say "eh I think Chauvin definitely used improper force but I don't think he intended to kill the guy", it's either "FLOYD WAS MURDERED" or "Based cop". It will spread from Minneapolis quicker than last year and more fuel will be added if there are more developments in the Taylor case in KY or against the rednecks that chased down Armed Robbery in Georgia last year.
To your second point, I have no doubt in my mind that Biden will gleefully put down BLM and Antifa, because to him it will be worth it to also get rid of any right wing groups at the same time. We may or may not see martial law go into effect (wouldn't actually surprise me this time considering Sniffin Joe has a fucking standing army parked in DC) and suddenly "Uncle Joe" will start to seem like the radical authoritarian that the commielites were accusing Trump of being.