Okay let's look at a couple things. What TYPE of lights are they? Are they incandescent, Compact Flourescent, or tube flouro? They should be a flourescent light of some type.

Next. RW cubes are fine if you treat them with caution! When you plant them in the soil, it is important not to bury them completely. They NEED to dry out between waterings, just like the dirt, otherwise you end up with a stem rot problem and *clunk* the plant falls over and dies. Very tragic, and avoidable.

More ventilation! You should be really sucking air out of there so it is refreshed constantly, and that will help with your heat too.

Pre=soakoing media is just for hydro, don't worry about that part.

Bottled water is not as good as plain tap water, and youdon't really have to worry about pH quite yet in a fresh soil right out of the bag. It is stabilized at the factory and remains stable for 4-6 weeks. Bottled water also has too much sodium and not enough calcium.

MG moisture control may hold too much water, and for the light and ventilation you [don't] have yet, I would say it is DEFINITELY going to take some finessing. Water LIGHTLY, and extra holes in the sides of the pot may help you. I would not use that stuff indoors, it's for patios that get hot and are hard to keep watered. Whether I would use MG at all is moot lol! Be real careful, it has ferts in it already so fertilize VERY WEAKLY at first!!!

Lose the water- it will just make it humid and sticky in there. If the clone gets real droopy, you can mist it lightly with tap water- Your clone was probably just not really hardened-off yet and the droop is likely to get better as it gets used to your conditions. You shouldn't have to mist much at all, just a day or 2 before it perks up and starts taking in moisture through its roots.