Hello, ( sorry I don't know your name)
Some thoughts
What kind of soil did you use ? What kind of drainage / bottom design did you set-up?

I have never put a plant into a tank with out doing a diluted bleach dip first ( leaves and cleaned roots) / then a long soak in a bucket of de- chlorinated water.
A little OCD --- ya think ?

Spider mites - in a red eye tank - I am going to say that these are a big deal since the frogs are not going to be eating them. You don't' want them crawling on the frogs - stresses them out - or nipping at the frogs.

Centipedes--- yikes -- I agree with you....... they hitch-hiked in.

Ants- not good - you will want to do everything you can - to get rid of these - most will bite.

Red worms --

The frogs the hate them or ate them ? Either way ----they won't hurt anything. If you get a really lot of them you might notice a distinct odor though?

Isopods and springs should be your best friends ! Especially if you have other dying insects in the soil.

I'm no bug expert; I'll throw Jeff a PM ........He will come to our rescue !

TWO QUESTIONS for JEFF :
1)is there competition going on! Will one bug ie ants - cause the demise of your very important Iso and spring population ?
2) Centipedes - What kind --a photo would be good ( if you can ) Is there is any worry about toxicity if eaten by the frogs?

Lynn