Hmm..putting them on a higher stand away from the kids reach will be your option. Most succulents just need warmth, bright light and good air circulation. Cacti once acclimated again outdoors can take direct sun and heat nicely, since that is their active growing time. Putting them inside that mini greenhouse will just trap too much moisture for them. It is different if it were the tropical succulents like epiphyllum or schlumbergera, those ones love better humidity levels.
I don't grow maranta, but often, like when I grow croton I find spritzing the leaves often early in the day helps them endure our very low humidity levels.
