I think we are into 'How many angels Dance on the Head of a Pin?' country. Who isn't intrested in talking to vetrans? There is the history intrest. If you don't know one end of a spanner from another you shouldn't own a military vehicle. If a member of the public asks a genuine question (It does happen, ocassionally) about a vehicle or what it would have been used for surley they deserve an intillgent answer?
If you look at the spread of information and variety of posts on the forum, you see the depth of knowledge. As for , I'll call it uneasyness, about certain Nationallity's being potrayed. That has to be down to the individual. But tolerance is important in our hobby, every conflict has at least two sides, and they are 'MILITARY' vehicles etc. (Though I admit to having certain biais)
Any good group, wether they call it re-enactment or Living history, will put a lot of work into research, to get things wrong is an insult to those who did it for real. I'd classify a re-enactment as a portrayal of a specific happening, living history as an encouragement to others to learn and understand.