[Daniel]

In clientscript/ckeplugins/vbimage/dialogs/image.js

To uncheck the dialog box

Find

label: me.editor.lang.vbulletin.retrieve_remote_file_and_ref_local,
              labelLayout: 'horizontal',
              setup: function() {
                    if (me.editor.config.vbulletin.attachinfo)
                    {
                        this.setValue(true);

Replace with

label: me.editor.lang.vbulletin.retrieve_remote_file_and_ref_local,
              labelLayout: 'horizontal',
              setup: function() {
                    if (me.editor.config.vbulletin.attachinfo)
                    {
                        this.setValue(false);

To switch the default tab (not necessarily tab order)

Find

var node1 = YAHOO.util.Dom.get("uploadtabs0");
                    var node2 = YAHOO.util.Dom.get("_uploadtabs0");

Replace with

var node1 = YAHOO.util.Dom.get("_uploadtabs0");
                    var node2 = YAHOO.util.Dom.get("uploadtabs0");