1. Don't know, sorry.

2. If the choice was F or long-haul J (as in a 34D) then I would say not much, since you get the AVOD, but short haul J is substantially below long-haul.

3. 777 and 2-class A330 are essentially identical in J.

Personally, if I wasn't pushed for time I would take the "F all the way" option.