Can a transport enter a hostile sea zone, that was cleared of hostile ships (during the combat phase), during the non-combat phase to pick up friendly units. For example: If the UK fleet N of Egypt destroys the Italian ships in the sea zone around Malta, during the combat phase, can a UK transport enter that cleared sea zone, during the non-combat phase to pick up UK units on Malta?
Yes. Two opposing nations can't have units in the same zone simultaneously. But if the units of one side were "eliminated" in earlier fighting, then the surviving (attacker) can move units into the formerly disputed zone.