> 5. make addresses randomly assigned

and

> 7. give every device its own public IP by default.

Both of these are optional. Don’t want them? Don’t use them - if you don’t configure them, it won’t happen.

> 6. make routers accept inbound connections by default

That’s not a new feature with v6.

> Like I own 8.8.8.8. You want to add more bits, fine, I'm 8.8.8.8.0.0.0.0 now. If anyone switches to the new thing, they know where to find me.

Now you (and everything in between) have to be able to handle packets addressed to 8.8.8.8 and 8.8.8.8.0.0.0.0, so you’ve done point 4 without knowing it.