There is a hide button on the vamx menu.  Press it and the menu will disappear and not talk back up when you grab something / press the button that normally toggles the menu.  Later when you wanted back you either need to find the very small show button, or more likely use the virtamate main UI's big show vamx button.  So if you don't want to grab to toggle the vamx menu, click the hide button on the vamx menu.

For full body / leg tracking you would need to have external trackers in order to control the legs like you are walking. Generally that means using vive trackers or something steam compatible.