I think the feat should probably apply retroactively. I dislike feats that are "better" or "worse" depending on when you take them. If this were a 3.0 feat, that ruling would make sense somewhat (int boosting magic items), but given that 3.5 removed that nuance, I wouldn't add it again in a different form.
That said, the feat may in-fact be "Stunningly Overpowered" compared to strictly the other core feats or perhaps the feats in the wizards splat-books that provide skill point boosts or racial skill points boosts.
Despite being "overpowered" for what it does, it isn't unbalanced. It is more powerful than comparative feats depending on your standards, but certainly wouldn't unbalance a game. Does a single +2 intelligence for the purpose of skill points alone unbalance a game? Probably not. Your not breaking any thresholds for skills, just adding a bit more choice and versatility.
As written, I'd give your feat a 2 if I could vote on the database. With the retroactive change being added (making it similar to improved toughness, but for skills instead of hit points), I'd bring that up to a 3. Fix the name to something that fits what the feat does (inquisitive has nothing to do with maxing out your jump skill), and I'd give it a 4.