You're welcome
To answer your question about where the crickets can go is simple. They either burrow into the substrate or hide under the water dish. So you always need to look thoroughly before assuming your frog is eating. Also you need to try and catch him in the act so you definetly know he is eating.
Both humidity and temp are equally as important. They need both for a healthy life. Misting a little more often will help with the humidity just don't watter log the substrate anymore. Pacmans are very sensitive to their tropical and subtropical environmental needs so they need to be maintained to the best of your ability.
I can't wait to see pics. Keep me posted.