From the PRD : The warpriest must meet the prerequisites for these feats, but he treats his warpriest level as his base attack bonus for these feats (in addition to base attack bonuses gained from other classes and racial Hit Dice).
I've attached a sample character : 6th level warpriest. He should be able to take the shatter defences feat (Weapon Focus, Dazzling Display, base attack bonus +6, proficiency with weapon), but he doesn't qualify for it on account of his BAB.
This is a very difficult issue to get around.
All Feats have the same prereqs regardless of whether the character chooses them from the general progression, or a bonus pool. In order to alter that, means coding in each "Exception" by hand. This is not a good model, because when the next book comes out, we have to remember this "exception" and add those new qualified feats.
If this wasn't tied to "bonus feats" only, then I could finagle something easier.
The monkey that coded the source up realized this and left a code comment and a user comment:
On the feat description " [NOTE: You may want to temporarily bypass feat prerequisites under House Rules in the Preferences when choosing these feats.]"
COMMENT: Varying prereqs depending on which feat pool feat is taken from too burdensome to implement
WORKAROUND: Suggest temporarily disabling feat prereqs in ability description
I have maybe ONE solution, but it sucks in the fact you'll be able to qualify for everything regardless of pool...
I made a hipchat room to discuss this issue for the team.
As you said this does not look trivial to solve.
The feat prereq bypass is a good enough solution for me. I kept looking for a way to do that, but I didn't think to look in the global options.
As a side note, shouldn't the ACG be added to the core supplements source?
Data Hack is only resolution. Sending to hipchat for consultation.