I know there are other Brawler prereq questions in long dead threads, but I couldn't find the answer to this proper.
Do Brawlers have TWF for a prerequisite in taking feats? And if so, how does this apply to passive feats?
Example in question: Two-Weapon Grace allows the use of your prior feat (Fencing/Slashing/Starry Grace), while your second hand is not free. However, by feat rules, while you do not have a feat's prerequisite you cannot use it. Brawlers only have TWF while using Flurry, so is their off-hand totally gimped except when Flurrying?
Example 2: Two-Weapon Defense, when weilding two weapons, you gain +1 AC. Does this mean because you lack TWF unless Flurrying, you gain +1 AC during Flurry, but all other times you are just holding two things like a tool?
I think when you're capable of using the brawler's flurry - i.e. armed with 'unarmed strikes, weapons from the close fighter weapon group, or weapons with the “monk” special feature' - then you should be able to count as having TWF for prereqs. I would apply this to both of your examples.
There is a designer response to this somewhere, but I can't remember where I came across it.
It effectively said you can take the feats, but they only apply when you are benefiting from TWF. Two-Weapon Grace would be fine during flurry as flurry can be done with one weapon.
TWD may work or may not, that would be a table variation I think.
Could you technically take ITWF as a feat after a 2 level dip into Brawler then?
I believe so, but again it would only be active during flurry, i.e. You couldn't gain the bonuses of TWF while using weapons not in the monk or close group without additional feats.
Update: Ended up just giving the character TWF anyway. Mostly to save confusion, and also cause we're using a little unchained, in that initial TWF is part of a standard attack, so having 2 hits outside of flurry has additional use.
Brawler TWF can be used as prereq for all TWF feats. The only caveat is the feats built on it can only be used with qualifying weapons.