Couple of questions...

[DVirginiana]

Not sure about the Dendrobaena. I think that's what they call Red Wigglers here, which are toxic to some reptiles. Not toxic to pacs, but emit a gross yellow mucus that many frogs don't want to eat. Hopefully someone else knows for sure

Try covering half the terrarium with cling wrap or something to keep humidity in. I usually end up re-wetting the soil about once a week to keep it at the right level of moisture. You want it to stay wet but not like, muddy.

For the Hygrotherm, you set the humidity you want it to stay at, and the sensor tells it how often to come on to keep it at that level.

[Lija]

not sure about worms.
as for the rest of Q, if you live in dry climate like me just a fogger controlled on hydrotherm is not enough. as DV said cover part of the top of the tank to keep humidity in. I need to flood substrate once a week, more in a winter and now when i got fancy pressure spray bottle, using it

hydrotherm works the way it needs to be, you have plugged a fogger in, so once a sensor gets lower humidity then needed it turns the fogger on, and turns off when humidity is a bit over, you don't need to worry about it. I programmed 76% on mine for pacs.
make sure your sensor is not where the fog comes from directly

[Pharaoh]

Thanks guys, here is a link about the worms (I haven't fed them to her yet until im certain its ok)
Livefood Small Worms (mixed spp.) | Swell Reptiles

I think I will get a decent spray bottle too then and dampen the substrate once a week.