Unfortunately, and I’m speaking from a professional point of view, it’s going to be quite hard to trace existing family.
The RAF records would have contained a next of kin and a person to be notified in case of death; but for most of the young people this was their mother and father respectively.
Your best bet is to hire genealogists in each country to trawl through BMD records to find any spouses and children, or even siblings and their children. Also it would be worth, if you can find where each man came from, putting an advert in the local papers as extended families tend not to move around too much.