I'm with you 'BB' - I think you're thinking along the right lines (if I may be so presumptious as to say so).

Capt. B - you're invocation of 'God Save the Queen' is an excellent debating point (you nearly got me there!) - but ('BB' to the rescue!), it is traditional to sing it on certain occasions - but not usually folk song singing occasions.

As for 'My Old Kentucky Home', well, I would cite 'A Rosebud in June' and 'The Famous Flower of Servingmen' as counter examples. Both are generally considered to be 'traditional' and both have been collected from trad. singers. Nevertheless, I believe that the former is from an early 18th Century play (can't remember which one) and the latter was supposed to have been written by someone called Laurence Price in 1656 ('A Book of British Ballads' by Roy Palmer - Llanerch facsimile edition 1998, p.187). I submit that both of these songs have been through 'the folk process' and can now make strong claims to be traditional.

I can't decide whether 'Kentucky Home'can be considered to be trad. or not - or, more importantly, whether 'the folk process' is still operating.