Looking at the Equipment Trick (rope) feat, it says that in order to use the lash trick, I have to have weapon proficiency (whip). Does this mean I need to have proficiency in the whip just from somewhere, or do I have to actually take the feat in order to qualify? (Same idea for the trick related to the spiked chain.)
EDIT: Equipment Trick feat for ease of reference.
Abilities don't, as a rule, care HOW you gain proficiency, the only thing they care about is that you are proficient. Weapon Proficiency(Whip) is simply asking "are you proficient with a whip?"
Being proficient with the whip (such as from being a bard) counts as having the feat for pretty much everything (As far as I know the only thing you can't do with class granted proficiencies is re-train/swap them out).