your questions regarding the dart frogs can easily be answered by searching through dendroboard.com's beginners forum. You will also find plenty of posts discussing mixed species vivariums....with many experienced and advanced owners strongly opposing the practice. I would consider myself still a newb in the dart frog hobby but after reading through many "can i mix species" posts, im convinced its a bad idea as well. Its a cool idea but ultimately very difficult even for experts to manage a system in which all species are kept at optimal conditions without stressing each other. For example, with your crested geckos, how are they going to handle the high humidity (80-90%) needs of the dart frogs? My advice...ax the paludarium/ mixed species idea and go with a well designed vivarium with a water feature and a small group of leucs or auratus darts.