The "-inne" forms sound rather dated to me. I'd say "Hun er skuespiller".
EDIT: I wouldn't be shocked to hear someone say "skuespillerinne", either, but I absolutely think "actress" should be an accepted translation here.
IMO, to extend the same gender-free courtesy to women as to men, one refers to a female actor as an actor. Either way, this sentence translates to actor.
[skuespileren] or [skuespilern]? There is a difference in pronunciation of this word in the whole sentence (1st option) and as a single word (2nd option) :)
Yes, words do tend to sound a little different when we say them quickly in a sentence compared to slowly and separately. Some sounds are swallowed and others flow together. The same thing happens in English.
That's not grammatical in English; it should be 'What is the actress called?'
An actress is probably an adult female. If you want to say this your way, it will be: What is she called? The actress! However, that is not the construction indicated in the question.