I agree with all 3 points SO MUCH.
I honestly don't think more promo would have made THAT much of a difference. It would've charted a bit higher, but i still think it would've flopped pretty badly.
The truth is, it just isn't that great of a song. They tried to make a Fancy 2.0 and failed miserably.
Iggy is very hated right now and she really just isn't that great of a rapper. Like you said, the best part of the song is the way Britney pronounces certain words and the way she sings her parts. It reminds me a little bit of how she sang in her older music, which I think was missing from BJ and even most of Femme Fatale. But at the end of the day, the song was very mediocre and Britney's parts aren't enough to save it.
Then they released a music video for it that got a ton of hate. Again, they were trying to do a Fancy 2.0, but what worked about the Fancy music video was that people didn't totally hate Iggy yet when that was released. Also, the Fancy music video was basically a shot-by-shot reenactment of the movie Clueless, which worked well because the 90's are very "in" right now and teens of this generation have seen Clueless. However, the Pretty Girls music video was a reenactment of Earth Girls Are Easy, which very few people in this generation have seen and therefore didn't understand the references and thought the valley girl talking parts were just bad acting.
I'm glad you posted this- I see a lot of people defending Pretty Girls, especially over on Exhale, and thinking it could've been a hit if it had been promoted properly. It isn't a bad song, but it also just isn't very good either. It's not the type of song you find yourself wanting to listen to over and over, and that's what Britney needs.