Well, insofar as it involves cutting out
PROCESSED, SIMPLE carbs, I don't see any problem with a carb reduction diet in the short term. However, the debate over the long-term efficacy of low carb dieting has pretty much run its course. Any diet that drastically slashes one of the three macronutrients is going to net you some weight loss for a while, but I still hold that low carb is not a sustainable option.
Two of your three stated goals are fundamentally incompatible with low carb. To build and maintain muscle, you need to work it heavily and periodically, and that means maintaining an adequate supply of glycogen. The primary source of muscle and liver glycogen is glucose, derived from carbohydrates in your diet. Don't deprive your muscles of the one fuel they are physiologically predisposed to prefer.
[Edit]
Just my opinion here, but you look pretty shredded already, if that avatar is current

If I were in your shoes, I'd be looking strictly for a mass increase right now -but that's just me.
<message edited by veggeep on Thursday, July 02, 2009 5:09 AM>