hook_node_insert() and drupal_goto conflicts with each other?
You can't use drupal_goto() in hook_node_insert() and other node_hooks too. The reason is that there is a queue of hooks that are executed on node insert and if you run drupal_goto() in some hook - all other hooks which goes after will not execute!

If you need redirect user after node insert to some url - implement hook_form_alter for node_form and add new submit callback $form['actions']['submit']['#submit'][] = 'my_module_submit_callback'. In this callback you will get $form_state with all $node fields and you can perform you redirect by specifying $form['#redirect'] = 'some/url'.