Are Swedish nobles styled in a particular way or is there no difference between addressing a count or commoner?
There is really no equivalence to the way British peers are styled. If I met a Swedish Count and I knew that he was very conservative, I would say greven (the Count) to him.
Has the Swedish court said anything about the styling of the 5 grandchildren of the King who have now lost their HRH?
How are Dukes styled in Sweden?
Will they be styled HH abroad (Norwegian example) or would they be addressed as Your Grace in the UK?
Nothing at all has been said about that, AFAIK. How Dukes are styled in Sweden? Well, up until now, all Dukes but one have been members of the Royal House. The only exception is the Duke of Otranto (d'Otrante) and I don't know if he has ever been styled in a certain way.
RW1