If the clones haven't hardened off yet, that might be one reason you're seeing the wilting. A 600W light is powerful, and rooting clones really don't need such strong light until they're fully rooted and producing new foliage. You might consider keeping the ones that are wilting away from the brightest part of the light's "footprint" until it's showing signs of healthy growth. Keeping the clones under a transparent dome also helps keep humidity high, which helps prevent wilting while the roots are establishing themselves.

As for when to switch to 12/12, that's entirely up to you and will depend mostly on how big you want the flowering plants to be. Some people go into 12/12 right away, especially for SOG-style grows, while others who are growing less plant leave them in veg a while longer to produce more nodes. Again, it's your decision.

Take care. :jointsmile: