The moths are great drinkers and will take moisture from the damp netting walls as well. Although they will pair and lay eggs without feeding the results are always better when the moths are well-fed. And it is always good to watch them drinking. While the larvae are keen on direct sunlight, the adults can become overheated, with a loss of fertility and no doubt some discomfort. I put sheets of cardboard over the sides to provide partial shade.
Space is no problem.
The females drop their eggs in the vicinity of their foodplant, comfrey, in the wild. In the cages they will drop them anywhere, a leaf of comfrey amongst the flowers may act as a stimulant. The inevitable aphids appear, drop their honeydew onto the sides of the bottles and the eggs stick to it. Also check out the flowers themselves. Normally the eggs are loose on the floor of the cage.