So, in Arena Kirk should have killed the Gorn and let the Metron destroy his ship because of the possibility that the Gorn might see mercy as weakness?
Yhere was no mention by anyone that they thought Nero could survive going through the black hole.
"Your ship is compromised.
You're too close to the singularity to survive without assistance which we are willing to provide."
Is Kirk simply making this up or should we assume that he's basing it on sensor information? If he's lying about this, is he also lying about the offer of assistance?
"Just kidding! Fire everything!"
There's a difference in how the ship enters the black hole, if the engines are operating, where the black hole is forming, how much red matter is used. Or are you saying that Vulcan wasn't destroyed but simply moved into the past? After all, it's even bigger than the Narada and the block hole was forming inside the planet, just like one was forming inside the ship.
I'd say that Nero had about the same chance of surviving as Amanda did.
What Kirk did was an execution of a helpless man. There was no indication that the Narada was even capable of charging or firing weapons. If they could, why weren't they?