There are no drawbacks to selective color that I can think of. The alternative is indiscriminate, wanton color which, as we all know, can get unruly and aggressive.
Similarly there are only advantages to curves, especially on the right body. The era of stick figure beauty is thankfully long past. Our culture now appreciates the organic esthetic of curves.
Beyond this, you may wish to consult the Photoshop forum. I suspect you'll get a very different answer there.