Hello, everyone!

As mentioned in my other post about getting 3 lime jello reed frogs in the introduction section, it was an impulse-buy and I do need some help on their care.
I have 1 really tiny one, 1 medium sized one, and 1 large one.
The size difference really makes it hard to choose what size crickets I need to buy.
So I got several pinheads, and several medium sized crickets.
I've been feeding them everyday about 5 medium sized crickets, and about 10 pinheads.
I dust them every time with multivitamin and calcium+D3 from exo terra.

I'm a bit concerned with how they're eating their crickets.
The first day when I put them in their tank, I didn't have any supplements, so I fed them un-dusted crickets.
In the morning, they were all gone so I assumed they ate them.
Now that I'm dusting my crickets, the medium sized one spits them out after hunting them and chewing on them for a bit.
Are they not liking the supplements? :/
Will they learn to like them?
I heard supplements are vital for frogs, so I do want them to eat the crickets. But they don't seem to like it.

I also got a fruit fly culture (hydei) because the dart frog forum said fruit fly culturing is a must.
I didn't feed them fruit flies because the screen at the top of my exo terra has holes that are too large, and I'm worried they will all crawl out.
I'm also thinking of getting a springtail culture going, but I'm worried they might all crawl out... is there any way to get around this?
I heard springtails are a must if I want my vivarium to be clean and free of frog poo... and mold.. and fungus.

Also, I've seen my large reed frog and medium reed frog wake up at midnight, crawl around, and hunt for crickets.
But I haven't seen the small one crawl about or soak..
I'm getting a bit worried because he's very tiny... I wonder if there's any special care for him because he's so young compared to everyone else?
He's about the size of my pinky fingernail.

Humidity in my tank is about 70 constantly.
Sometimes it drops to 65 during the day, so I turn on the fogger for a few minutes in the morning.

Today, I'm seeing the medium sized frog crawl about, but the large one and small one don't even seem like they want to wake up.
Should I be worried?

Sorry for so many questions.
If I need to clarify some things, please let me know.
If anybody else is keeping reed frogs (hyperolius sp), please let me know.
I'd like to know your set up, and what you do to keep them happy.
Basically, I want to know their general care.

And also, please be patient with me when I don't understand things.
This is my very first frog, and I probably have much to learn.
Thank you!!