Ah yes that's correct regarding luggage. A SYD - CTS via HND would follow their Int'l luggage allowance where as separated it would not.
Regarding the terminals, ANA uses both T2 and T3 for Int'l (T3 is the main Int'l, T2 is effectively ANA and friends domestic terminal with limited Int'l).
The Sydney flight is often at T2 but not always hence why they say it can be either.
On an off note, you can randomly get the Pikachu livery plane and it's extra freebies as SYD-HND is one of its routes.
