Add custom function to a theme with child theme’s functions.php

I think the problem is with your choice of hook and conditional statement. Try init and remove the !.

function themeblvd_disable_admin_bar() { 
    if( current_user_can('edit_posts') )
        add_filter('show_admin_bar', '__return_false'); 
}
add_action( 'init', 'themeblvd_disable_admin_bar' );

Looks like your conditional is also wrong for the redirect

function themeblvd_redirect_admin(){
    if ( current_user_can( 'edit_posts' ) ){
        wp_redirect( site_url() );
        exit;       
    }
}
add_action( 'admin_init', 'themeblvd_redirect_admin' );

If these snippets work as tested please mark this answer as accepted and up vote using the arrows to the left. Thanks