I spot clean and full clean once a month, how many watt is your UTH? I think it won't be enough. I'm working on my tank and plan to heat it with a UTH and a infrared bulb, the UTH working 24/7 and the IR bulb plugged into my thermostat. You should not be worried about mold, I've owned my oldest pacman for 2 years, kept her too moist for quite a while and never even seen mold. The only terrarium I see mold in if I keep it too moist is the one of my crested gecko and that's only on the jungle vines.
Also, don't be worried about locusts or dubias if your pacman loves nightcrawlers, most of us envy you. Offering the pacman food and occasional fuzzie might be fun as a mix for your frog. But remember with fuzzies, don't offer them more then once a month, even less I would advise.