While they could have killed off Riker, I don't think it really would have made much difference. Nemesis's problems were more systemic than a mere plot point like that. It wouldn't have solved the "we're watching TWOK again" syndrome. That was the biggest crime of the movie, to me anyway.
Who plays the Spock role is irrelevant, really.
Who plays the Spock role is irrelevant, really.