Sorry for not thanking you all for the great advice - been insanely busy.
Corozal is a protagonist, but it's an ensemble piece - when he arrives, tensions between the others explode. So yes, he is definitely important.
Jem, great point about conflicting opinions on him before her arrives - yes, there are conflicting opinions. I want the reader to feel ambiguous as to whether he's good or bad (throughout the book, in fact).
Tiger, glad you think that
Alexandra, I have read Anna Karenina, but not for many years - could you remind me what delayed MC means in that context?
Thanks again
Andrea