Ive had my African Dward frogs for 6 years now and there healthier than ever. They love a PH level of 7.8 and that is when they thrive, they can become very un-active in anything under 7.5.
I agree with you on the Escape attempts front and have had a few myself. The thing is about these little guys, they dehydrate so quickly, we're talking minutes here. Whilst cleaning my tank once one of the little chaps managed to escape (Paul, After Sir Paul McCartney), - And wedged himself under the door, i got very scared and didnt move it because i didnt want to crush him. After 40 seconds or so he freed him self and continued to throw himself into his next step like some possesed devil. They really cant hop like other frogs, its rather pathetic to watch actually, they just throw there hole bodyweight at the front legs, move about an inch then flop back down. Back on topic, by this point he had dried up! and when i finally got him to freeze he had stuck himself to the floor so firmly that i couldnt remove him. So i wetted my hands with the water from his tank and managed to grab the little bugger. Hes ok now, that was a few months ago. They are very hardy, just as i said before, dehydrate very quickly. I would reccomend buying Pebbles rather than gravel to, as mine decided to eat my gravel on day 1, Not good!.
Put somthing fairly heavy on the lid of the tank, not paperweight heavy. A model car for example, just to ensure if he was to try and escape he cant.
Mine live on a diet of strictly bloodworms. Its the only thing they enjoy, and since they are bottom lurkers they wont touch anything that doesnt sink. I buy frozen food that lasts 1-2 months for £2.35 (UK) And feed them live bloodworms 4 times a year as a treat.
Hope ive help remotely? Il help out in any way i can.