We are not sure this is allowed in the tab name area (not checked yet). This may be possible in the right section (with the Beat, BPM and Master Faders).
That would be fine. Ideally it just needs to be on the main page all the time regardless of what tab you are on. You should not have to click into a tab to access the "freeze" button. Often times during a show, you need to hit it at a moments notice.