57mm is not the way to do it. The 57mm shell is relatively light weight and is used almost exclusively with the idea to defeat small craft (i.e., for the littoral patrol or policing role) and has far insufficient range to be bombarding land targets. 5-inches is what you're looking for, but inappropriate for a ship like this.
Actually the type of gun you have is appropriate for a ship like this, just that the role you describe is not.
Also you deleted the wrong radar - I'd rather have kept AEGIS.
I'll heed the radar thing. Good thing the original drawing is in the first post.
As for the 57mm, it is not the main fire support element. Long-range strikes on the tougher nuts would be conducted by 127mm, missiles, and airstrikes. Once control of the air and sea is established, the vessel can pull in close to the shore (but still far away enough not to beach itself) and fire at closer ranges and perhaps even conduct airburst attacks on hostile combatants on the shore.