A sweed, or sweedish
Someone from Monaco is a Monegasque.
In Spanish, that means that you call someone "vos" - a form of "you".
A form-filler.
Vatten.
If they gave you the number where they would be staying, you could call that. Alternatively, you could text message them. You could call someone in Sweden who knows them. Or, you could pre-arrange for them to call you. Some mobile phones can send e-mails, so you could reach them that way as well.
Yes; they are very common. Might not have originated from Sweden. But in Sweden that's what they call pancakes.
Swedes
In Sweden, the closest thing is Jultomten ("The Yule/Christmas Gnome").
There is no official name for people form South African provinces.
Swedes or Swedish or more generically Scandinavian (A person from Sweden, Norway or Denmark)
Sweden
Swedes, or Swedish.