I wouldn't call crested geckos stupid proof that's for sure. Maybe less dedication then say a chameleon. Its very easy for some one to kill a crested without paying attention to heat and humidity bad sheds ect. They get MBD from bad diets and people feeding only insects. So to tell someone they are stupid proof is somewhat misleading. To me Vieled chameleons are what you explain as stupid proof to but to others in the Health section looks like a struggle for them. Either Way to each their own.
That being said I like to use the small repti breezes which are 16x16x20 I think for even single adult males. I also use the 18x18x24 exo terras. Crested geckos shouldn't have much trouble finding their food as they eat Crested Gecko Diet and you should place it somewhere they won't walk in and they learn exactly where its at and will be waiting for you to fill their bowl. Insects are treats They don't need them. Use Repashys Crested Gecko diet which you mix with water 2/1 or something like that. Has all the calcium vitamins and nutrition they need. Crickets are to keep them excited and give them little time to hunt.
I also kept babies in plastic totes too that I stood up tall ways and drilled holes all around.
I just don't want people to get the wrong idea,yes they are super easy to care for and awesome gecko but I wouldn't trust any stupid person caring for my geckos is the way I looked at it. I got the idea what you meant though