> If yes, how could this manifest itself if a bad actor had a lot of ETH and tried to manipulate the chain?
With the current price of ETH, it’s unlikely that a single entity could gain enough of the supply to do anything like this, but it is a valid concern for smaller chains.
> Could they theoretically jump favored transactions to the front of the line and/or charge less fees for their own transactions?
Block proposers can already do this. How often you get to be block proposer, is proportional to the amount of stake you have.
With the current price of ETH, it’s unlikely that a single entity could gain enough of the supply to do anything like this, but it is a valid concern for smaller chains.
> Could they theoretically jump favored transactions to the front of the line and/or charge less fees for their own transactions?
Block proposers can already do this. How often you get to be block proposer, is proportional to the amount of stake you have.