[yanmaani]

> It was voted for by 8000+ validators.

Which parts of this are checked by the client software, and which parts are just checked by interested humans in the block explorer?

There's a trade-off here. If you require 8000 guys to all vote in favor of your block, what does the client do if it only sees 7999?

> which wouldn’t be supported by any ETH1 deposits ... signed by 260k freshly generated public keys

You misunderstand. What happens if some of those private keys get compromised? In Bitcoin, if I sell my miners to someone else, it's not like they're radioactive waste that has to be buried. In PoS, someone can cause quite a bit of damage with keys that ostensibly don't contain any money. And because I've already withdrawn, I have no reason to care.

[pshc]

The system is fault tolerant. You typically get 99.X% participating. Any validator that doesn't perform their duty in a timely fashion is penalized and eventually ejected if they are disruptive.

Those private keys are useless unless you had something like 50% of all the active validators' keys. So, hundreds of thousands of private keys hacked. You're not going to be able to damage consensus using a few old leaked private keys. The best you could do would be to slash some active validators and get them ejected, but the chain would carry on finalizing without them.