The vandals did not invade North Africa "Omaha Beach style"...
They were invited by the rebellious general Bonifacius, who was in rebellion against the central government at the time. For all we know, he provided them the ships himself.
As for which naval battles could have been different?
Against the Goths in Black Sea in 256 and the Heruli in 267 would have perhaps enabled them to achieve victory, although the Romans won those wars regardless of their early naval defeats.
Battle of the Hellespont (324) may have ended differently, although that was a civil war between Constantine and Licinus where the latter was already on the back foot. Considering that the eastern half of the Empire, that Licinus controlled, was the most Christianized, the long-term trend is inevitable, even if Constantine is forced to settle for half the empire.
Cartagena under Majorian could have had some sort of impact, but it was basically the Vandals catching the Romans with their pants down. Greek fire wouldn't have changed a thing.