^Well, Nero didn't blame the Federation for deliberate destruction, but for betraying its promise to save Romulus. Arguably that sense of betrayal would be more strongly felt toward a nation that the Romulans had grown to trust as a friendly power. "You said you'd help us, but you didn't really care, did you?"
We saw that kind of thing with Andor, true.
I guess that a lot depends on what sort of relationship Nero had with Spock. Countdown
presented Nero's hatred of Spock being something very personal, a product of their early collaboration in trying to deal with Hobus. In such a scenario, Nero going after Spock while the other Romulans don't would make sense.
Nero probably won't be the only Romulan who feels that way. But probably other Romulans won't be able to get their hands on supplies of red matter and thus won't be able to act out their anger so destructively.
Much depends on what Nero departed with. Countdown
has him being absurdly well-armed even by late 24th century standards, his mining vessel retrofitted with Borg technology. But then, as has been said repeatedly, Countdown
is not considered canonical in the novelverse. (Conceivably a late 24th century mining vessel could be quite well-armed relative to mid-23rd century vessels, even warships.) So who knows how exceptional his armaments are?
And the surviving Romulan government would probably be more inclined to accept whatever aid they can get, including Federation aid (though with the Pact there to come to their assistance, they may not feel they need UFP help).
Much also depends on the sorts of continuity. If Kamemor does escape Romulus and there's continuity in government, then relations would be stabler than if the Romulan government was decapitated.
(So, in sum, all this speculation is basically useless since we don't know what will be established in the novelverse?)