CKEDITOR image insert disabled on adding custom plugin for image

I have written my own custom plugin for inserting images in CKEDITOR. I disable the image button in toolbar . I use the editor.insertHtml() function to insert the image from my custom plugin . When I remove the standard image button from the toolset it disables insertion of image tag in the CKEDITOR box . All other html tags are accepted but for the <img/> tag .

This is my config(without the 'Image' in config.toolbar) :

CKEDITOR.editorConfig = function( config )
{
CKEDITOR.plugins.addExternal('insert_blank','http://localhost:3000/assets/ckeditor/plugins/insert_blank/', 'plugin.js');
CKEDITOR.plugins.addExternal('qimage','http://localhost:3000/assets/ckeditor/plugins/qimage/', 'plugin.js');
 config.extraPlugins = 'insert_blank,qimage' ; 

  config.toolbar =
    [

        { name: 'basicstyles', items : [ 'Bold','-','Italic' ] },

        { name: 'insert', items : [ 'insert_blank.btn','-','qimage.btn'
                 ] },
];
   config.keystrokes = [

    [ CKEDITOR.CTRL + 75, 'InsertBlank' ],    
    [ CKEDITOR.CTRL + 85, 'qimage' ], 
];  

        config.height = 300 ; 
                config.width = 350 ; 
                config.removePlugins =  'elementspath,resize' ;

};

Is there a way to enable image tag insert ?