> Limited liability allows companies to take risks that no sane individual or group of individuals would take on their own.
No, limited liability allows people to use corporations as a tool, which includes misusing them to take risks that should not be taken.
> Limited liability is precisely the factor that lets corporations act as agents instead of extensions of individual or group human goals.
No, limited liability is the factor that lets people use corporations to further goals that benefit them, including goals that are harmful to society as a whole.
It's still people doing things, not corporations as magical agents independent of people. Thinking of a corporation as doing nefarious things as a separate agent from the people running it just distracts attention from the actual problem, which is people who want to do nefarious things misusing whatever tool they can.
None of the things you describe make corporations magically able to do things without the group of people that make up the corporation doing things.