Mbo_Form - created object. Mbo_Form it is written on VF on the custom controller. As clicking on the tab or by clicking on Mbo_Form record this tab, redirect when loading a standard page on the custom page?
You can override those settings in the custom object setup. For example, you can override the settings for the standard tab to send the user to the custom VF page that you've created. You can do that by clicking on the edit link next to the tab of the custom object in the "Buttons, Links, and Actions" section under the custom object's settings. You can do the same for the other types of links that you've mentioned. Here's the link to the help document that provides more details: Overriding Standard Buttons and Tab Home Pages https://help.salesforce.com/HTViewHelpDoc?id=links_customize_override.htm