Did this live sand come in a bag from the LFS? Most of that stuff is only marginally alive by the time you get it anyway.
It's possible there has been some die-off from sitting out, but it's still good argonite sand. As long as you're not smothering a layer of live sand that's already in there, go ahead and use it. If this system already has fish or in it, you may want to add only a small portion each day, in case there's an ammonia buildup in the sand from a die-off.
If you want to make your sand really "live" you might order a detrivore kit to add to your sand.
CC can collect debris pretty easily, and increase your nitrate levels. Most people find they don't like CC and have to try to remove it later. It may also feel rather sharp to snails and other soft-bellied critters.