When I use CFLs I have them Up, Down, along the sides, everywhere. You can put those lights any place your imagination will let you with clamps and fixtures suited for it. I use white board from Walmart for the floor and sides. Holds together with duct tape. Great reflectance and great light penetration.
As for CO2, I never really had a test or experiment. Just tried it and not tried and decided not to fool with it in the future. I guess under certain high tech circumstances you will see a noticeable amount of growth, you know extreme heat in a sealed room etc, but for most folks it is just a little snake oil to add to their op. I like to make wine with leaves, sugar and yeast, but I do not depend on it.
In a grow like your's I say keep it simple. Your call though.
Go easy on those new clones. Just give them the seasoned water you have and not much else. Don't let them dry out. You know clones are usually under rooted and need special care that they do not dry out. you have a weeping clone that is thirsty and chances are you lost her.