"...parents were in the Hitler Youth."If it's a basic statement of fact like this, and the statement is correct, then can't really see any real problem.
However, it may depend on the context. If the recipient of the statement is an EU national, say, and the comment was made in the context of a 'go home' kind of argument then it might be considered racist.
"
At least none of my parents were in the Hitler Youth."
Again, fair comment if based on a statement of fact, but again the wider context might make it racist.
I doubt either of the above would be considered defamatory, though, if based on true facts.
"
ACHTUNG baby...I run a decent firm....not like NAZICABS from Melton."
Definitely defamatory if the whole firm is being characterised in this way (assuming the firm is actually named or anyone could work it out). Also defamatory if the individual was called a Naz
i purely based on the activities of their parents.
Not sure how this might impact on 'fit and proper' status, but again that would depend on the context. And, of course, fit and proper status is largely based on the opinions of individual councillors, so it's a bit like how long is a piece of string...
Would certainly be unusual if a council took action based on something like this, though, which is essentially just old fashioned namecalling, but in the social media era it's up there on Facebook or Twitter for the whole world to see.
In my opinion, at least