Thanks to everyone who's chimed in here. I've seen many good points made about this feat as written.
I probably ought to stick up for the player who proposed this feat -- he's not a power-gamer, and doesn't haul the latest splatbooks and Dragon magazines to every game session. He certainly wasn't trying to scam me.
And I probably ought to explain that my campaign is low-magic, low-tech, and low-power. My player's character is 7th level and has NO magic items yet. There are no "mighty" bows. Longbows, for that matter, are an exotic weapon. Y'all get the drift.
So in our campaign, archers have never become the terrifying threats that they evidently are in other campaigns -- so this proposed feat never really set off my DM balance alerts. I was genuinely surprised by some of the accounts I read in this thread. Which is why I'm DOUBLY glad I posted this feat here.
If possible I'd like to salvage the feat, but I’m beginning to suspect that nerfing it will make it useless. Such things happen sometimes.
Based on Andion Isurand's comment, I'd change the prerequisite to Dex 13+.
SylverFlame, I like all three of your suggestions, but I need to think a little more about the 30' range restriction.