ken-ichi said:
I would look to similar attack options that you can do with full attacks and base my decision around them. I can look at Power Attack, Combat Expertise, Fighting Defensively, Two Weapon Fighting, and Whirlwind attack. All these options can be done with a full attack and all these options affect your to hit rolls until your next turn. As you still get the AC bonus from Expertise and the damage bonus from PA on your AOO, these options continue to apply therr effects until your next turn.
(The to hit penalty from a flurry also apply until your next turn. As I quoted earlier in the thread "
each other attack made that round" [NOT "each other attack
made as part of the flurry of blows"] suffers the relevant penalty.)
You are, however right that these examples are a help when making a decision. In order to get more than one attack in a round you "must use the full attack action". You can make secondary natural attacks when using two-weapon fighting. (Not in dispute.) Two-weapon fighting requires that you "use the full attack action". Thus, the fact the a flurry of blows requires the use of a full attack action does not indicate that you can't make secondary natural attacks when using a flurry of blows.
But maybe the phrase "when using X" means that, for some reason, you are considered to be "using X" the entire round?
"Creatures do not receive additional attacks from a high base attack bonus when using natural weapons" (MM glossary).
If you can't "use natural weapons" without "using natural weapons" in the entire round, then you can't get additional attacks from a high base attack bonus when using secondary natural attacks. But that's not the case, is it? Hmm.
ken-ichi said:
Whirlwind says: When you use the Whirlwind Attack feat, you forfeit any bonus or extra attacks granted by other feats, spells, or abilities.
Flurry says: When using Flurry of Blows, a monk may attack only with unarmed strikes or with special monk weapons. Both work in a similar but different manner. Whirlwind limits the number of attacks you can make, while flurry limits the weapons with which you can make any of your attacks.
You make a good point about the quoted part from Whirlwind Attacks. However, that's tagged on after the main text, which makes it clear that you also "
give up your regular attacks" (implied: in the round). Furthermore, it is clear from the context that the use of whirlwind attack keeps you from making other attacks in the round. There's no such contextual clarity in flurry of blows. (Remember - I'm not the one insisting that a rule exists. I don't have to prove the negative.)
If the quote on "using" natural weapons above did not convince you, how about the following rule quotes...
"When using the weapon you selected, your threat range is doubled." (Improved Critical)
Would a single attack with a weapon you have the Improved Critical feat for double your threat range for
all attacks in the same round?
"When using a weapon with which you are not proficient, you take a -4 penalty on attack rolls." (Several feats)
Would a single attack with a weapon you are not proficient with give you a -4 penalty on
all attacks in the round?
"When using a spiked chain, you get a +2 bonus on opposed attack rolls made to disarm an opponent (including the roll to avoid being disarmed if such an attempt fails)." (Spiked chain)
Would a single attack with a spiked chain give you a +2 bonus on
all opposed attack rolls made to disarm an opponent in the round?
I think the self evident answer to all these questions is "no". So, the words "when using..." are not secret code for "the following applies in the entire round where you're using..."