I just have to clarify that you need to disinfect the cage before putting your pacman in since you had another frog previously in there.
to answer your questions; the soil should be moist. If you squeeze the soil with your hand and water comes out than it is too wet.
misting should depend on the humidity. I keep mine between 80-90%. never let it get below 70%.
82-84 is fine but do not get above 85.