Remove Dynamic Widget Metabox from Custom Post Type Edit Screens

Source: 10+ Useful WordPress Code Snippets

Remove Featured Image Metabox from Custom Post Type Edit Screens

Source: 10+ Useful WordPress Code Snippets

Remove Metaboxes from Custom Post Type Edit Screens

Source: 10+ Useful WordPress Code Snippets

Remove Dashboard Widgets

Source: 10+ Useful WordPress Code Snippets

Remove Comments menu from Admin Dashboard

Source: 10+ Useful WordPress Code Snippets

Custom post type custom icon