Again, for all the slack people are giving KG about playing the 3, I don't see how anyone thinks he'd be any worse defending the 3 than Walker or Giddens. This guy, after all, is the best defender in the NBA. And with his height, he could stay a step off quicker 3s and still get a hand in their face.
Between House and Daniels, they should be able to cover most of the backup minutes at the 1-3. However, if the odd 5 minutes pop up in a game that matters at the 3, I'd rather see KG slide to the 3 for 5 minutes and have Baby get a few extra minutes at the 4, than see Walker or Giddens get those 5 minutes. (Keep in mind, I'm talking about games that matter, not blow outs in November.) (Also, we're talking about KG playing 5 minutes per game at the 3, not 40, so I don't see how the "wear on his body" issue even comes into play.)