You have 1 segment too many in Europe, easily fixed by dropping BCN-VCE. You could alternatively drop SVO-HEL but that is likely to be a much higher fare. The problem isn't the flight limit per continent, but a special rule that says you cannot purchase additional flight segments in the continent of origin -- so you are limited to 4 with 2 stopovers. There is no way around this rule (except to start at a different continent).