Thanks for the feedback, everyone. I guess for now I'll focus on losing fat/building muscle, and see what happens with the tummy.
Maybe I can go on Extreme Makeover for a tummy tuck. I could probably use some more cleavage while they're at it anyway.
As far as checking with the doc before exercise: I did, and she said
"feel free to resume all activity" and "listen to your body and rest when it tells you to". She didn't offer any specific exercises for getting the abs back in shape, but then again she's an OB-GYN, not a trainer.
I'm still open to a specific routine if anyone has a tried-and-true way to fix the poor ol' abused abs.