The issues with Iceberg don't stop there. More importantly, even at the end of the plot, Luffy and the others didn't go for the kill on Iceberg. Otherwise, Iceberg would have surely died. This is because the World Government didn't want Iceberg dead. Even though the blueprints of the Netherworld King had been destroyed, the World Government still didn't want Iceberg to die and continued to let him control the City of Seven Seas.
Iceberg is currently: running an illegal business (helping Pirates build and repair ships), holding a legitimate position (mayor), and making a lot of money quietly (Galley-La Company).
For a person like that, if someone said he was a warm-hearted man of justice, Su Xiao would never believe it. Moreover, Galley-La Company doesn't reject anyone in their external recruitment.
Thinking about this, Su Xiao already had some preliminary plans in mind, with Iceberg playing an important role in them.
Iceberg removed his blindfold and looked at the doorway.
