So, in theory, stopping the Narada would work. Spock would just have to wait around for the ideal moment to travel forward to before he left, so like BTTF part 1 he arrives back as soon as he leaves and watches himself and the Narada disapear.
However, theres a wibbly wobbly flaw in that. That would create a loop of Spocks going back creating more timelines.
At the end of "Back to the Future," Marty saw himself vanishing in the Delorean at the
Lone Pine Mall. But in the original timeline Marty had gone back in time from the
Twin Pines Mall, before crashing into one of the pine trees in the past.
So the Marty that disappeared at the end was a different Marty, one who had grown up in a town with a Lone Pine Mall, and who had a brand-new truck and a father who was a successful science-fiction author.
So, really, Marty didn't see himself go back in time; he saw a different version of himself go back to a different timeline. If "Marty 2" goes back in time and crashes into the pine tree again, then he would still return home to a Lone Pine Mall, so to him it would appear that he is trapped in a causality loop. But to "Marty Prime," who is the star of all three movies, he is in a wildly different future than the one he left, with a different family, different car, different Biff, and a different name of his mall.
So "Marty Prime" has set into motion a quasi-infinite temporal regression, such that "Marty 2," "Marty 3," "Marty 4," et al., are all virtually identical, and do not notice any changes to the timeline when they return home. The only way to break this cycle would be for, say, "Marty 27" to get back early and kill "Marty 28" before he has a chance to go back in time, thus preventing another loop from starting.
Likewise, even if Spock went back, stopped the Narada when it first arrived, then traveled forward into the future (like Picard did after stopping the Borg in "First Contact"), he could either get back just in time to see himself and Nero get sucked into the black hole again, or he could get back a year earlier, help his one-year-younger counterpart complete the "red matter" device earlier, and save Romulus, thus preventing Nero from going back in the first place. Then Romulus and Vulcan would still exist in the 25th century, and there would be two Ambassador Spocks, one a year older than the other, and no new timelines would be created.
(Of course, that would be a massive violation of the Temporal Prime Directive.)