1. When feeding by hand, my leo, Chibi puts away quite a few mealworms. Normally around 7-10, sometimes more. Basically, feed your gecko as much as it will eat within 15min or until it grows uninterested. You should also make sure you are dusting from time to time. Mine gets dusted crickets about 3 times a week plus dusted worms about once a week.

2. I don't think they drink a lot of water. Mine hardly ever drinks from the dish and mostly enjoys walking through it.

3. I clean my enclosure every time I see a poo and I clean the whole cage once a week. The whole cage is due for an entire scrub down soon.

(Oh and your leo has the same name as a bearded dragon I had years ago. I love that name)