I have a 2006 mustang gt, is it possible to shift gears without the clutch pedal after1st?

That's what a guy told me who works with cars alot. He said after I engage the first gear with the clutch pedal I can shift in and out of gears without the clutch as long as I'm moving. But once I stop I have to use the clutch again to engage it to start up again. Does anyone know if this is true?He also said pushing the clutch pedal all the way down is unnecessary, he said you really just have to depress it a few inches down to disengage the clutch, is that true also?