Why a naval Tornado would effectively be a new aircraft

If Britain had supercarriers, would a naval Tornado be better than the F-14 in every respect?

There is no simple answer, because a viable naval Tornado would be structurally different enough from the land aircraft to amount to a new design.

The answer returns to the difference between modifying an aircraft and creating a genuinely carrier-capable airframe. Arrested recovery and catapult launch would require stronger landing gear, structure, and many associated systems. A naval F3 might perform a broadly similar fleet-defence mission, but it would no longer be the land Tornado used as the comparison baseline. Claims that it would exceed the F-14 in every category are therefore impossible to support until the new naval design actually exists.