user tabs customization
I am unaware of any module that does this for you. So, you'll need to use a little bit of code to tweak things. What you need to do is implement hook_menu_alter() in a module to alter the way the tabs are organised. In particular, you will need to swap the menu type of the default tab and your video tab. The types in question are MENU_LOCAL_TASK and MENU_DEFAULT_LOCAL_TASK; i.e., change the default tab to MENU_LOCAL_TASK and your video tab to MENU_DEFAULT_LOCAL_TASK which should set the latter as the default. More information on these constants are provided on the hook_menu() page.