It's presumably mutated into something much weaker so it can spread much more easily; the ultimate goal of a virus

Wrong, that's deliberate propaganda that was pushed into media by certain groups. I won't elaborate more on that (about who pushed the propaganda and why, it's largely personal opinion) and I am lazy, I'll just say a few words. Polio, ebola, small pox, rabbies, the list goes and on. None of these viruses, if any, ever got "weaker" despite being with us for thousands of years. Furthermore, there's no evolutionary pressure for corona to take that path since it had a small fatality ratio from the start (let's say 1 %) and that often weeks after the host was already infectious and had spread it. With people getting infected again and again it's mostly pure luck what happens, although there's definitely a pressure to avoid our immune system responses. We used to get a different variant every 6 -12 months now it's a new one that takes ground every one or two :)

I am too busy to comment on the rest right now, maybe I'll come up later today