Translation:If his handsome friend quickly arrives here, everyone will be happy.
I'm seriously confused by this whole skill. In the Tips & Notes it says that the Simple Actual Conditional (so here varsa) should be translated as If I were to arrive, but this was marked wrong and the correct solution which was given (arrives) implies that the verb in Turkish would instead have been varırsa, what the Tips & Notes call Simple Habitual. Have I just got everything confused here or is there actually an inconsistency?
I think that there only is a little difference using varsa or varırsa here. In the first case the meaning is that it is not really too sure that the friend will arrive quickly. May be he has to do a lot of other things before he can come. If you use varırsa it means it is more possible that he really will arrive quickly.
I have the same confusion, even after starting on C1 level Turkish ;) I know that at beginner level we learn that a large vowel harmony (accusative ending, de facto) is used to indicate a specific object... So "portakal seviyorum" = I love oranges, "(bu) portakalı seviyorum" = I love this orange.
I believe that what we have been taught at the beginning, was just an early version of the later proper exercises on cases. Because you would use a different case if the verb demands it. So in the example above: "(bu) portakala bakıyorum" = I am looking at this orange.
So - you will never make a mistake if you forget about the first bit (learning that the ending means "THE" ) and instead just transform the object into the case that the verb needs, if you are talking about a specific object.