[Ruphin]

Proof of Stake and Proof of Work only impact the consensus model of the network (i.e. how new blocks are added), but for network participants that do not participate on consensus there is no difference. Just like in Bitcoin or in Ethereum now, you can run a node without participating in mining or staking.

If you run an Ethereum node now, it will still be the same after the Merge, and not somehow less valid. It will still check the correctness of all the transactions, as it does now.

I think a large cause of this confusion is the "validator" terminology; calling nodes that produce blocks through staking validators makes people think that normal nodes don't validate or check anything, but this is not correct.