Q267 Bardic Knack and Knowledge Devotion.
Does this work? Letting you not take any ranks in knowledge skills and still get a nifty +x/+x to attack and dmg?
A267: No, that doesn't work. Bardic Knack specifies that to use it on a skill that doesn't allow untrained checks, you must have one actual rank in that skill.
Knowledge (Int; Trained Only)
Now, you could go ahead and put one rank in every skill, and then just rely upon your bardic knack from then on. But, it does actually require you to invest a rank in each knowledge skill you wish to use. That's only 6 skill points to cover all the skills that apply to different creature types.
Q 268: A vampire has the Spell Drain feat from Libris Mortis and drains a caster, gaining the ability to cast Stone Skin. Must the Vampire provide the expensive material component? The feat says nothing about needing to provide the components, and says its effect is treated as though the spell were cast by the drained caster. It also specifically mentions not needing the requisite ability score to cast the spell. The feat does, however, note that "you gain the ability to cast that spell once (as if you had prepared it)."
I'm not positive, but the "as if you had prepared it" part makes me think that you must provide any components.