diaglo
Adventurer
Patryn of Elvenshae said:I think it's all of them.
The buckler mentions a "-1 penalty to attack rolls," not a "-1 penalty to attack rolls with the bucklered arm" or somesuch less awkward wording. (Specifically, it says: "This penalty stacks with those that may apply for fighting with your off hand and for fighting with two weapons.")
The penalties for Two Weapon Fighting apply to both the on- and off-hand. Similarly, it looks like the buckler penalty does, as well.
but you only lose your buckler bonus to AC when you attack with the arm the buckler is on.