They should have gotten a writer that actually UNDERSTOOD Trek.
Bring someone who understands story telling.
Yeah, that would have worked too.
Shinzon's motivations are dramatically arbitrary; he does not target Earth because the Federation has ever done anything to him. He targets Earth because the plot demands it, irrelevant of whether or not it's consistent with the rest of his depicted motivations.
It really does make no sense.
I think it would have been better if Shinzon's plan was actually to destory Romulus. The story could have been the crew defending an enemy and ending with the starting of a friendship between the two cultures. It certainly would have been more interesting than defending the space hippies in Insurrection.
I just can't get over how much the clone and B4 plotlines sucked.