Frogeyes,
The tank looks great! You have gotten some good advice from other Red Eye keepers so I won't retread things that have been suggested.
You won't regret going with a false bottom - Even if you decide to flood most of it with water to help with the humidity. False bottoms are the way to do in my opinion.
For soil - I saw where you were (at least at the time of the posting) were looking at doing ecoearth. I would recommend you use ABG mix or the NEHERP custom mix soil. It will be much better for the real plants you plant into it and will also be great for a springtail colony to live in. Springs are great with Red eyes. The reds don't feed on them, but the springs will eat any frog poop that lands on the bottom, any dead feeder insects, and decaying plant life. The Springs waist is great nutrients for the plants in the soil. It in a way create a little self sustaining eco system at the soil level

. Just buy a spring culture and dump them straight into the soil and they will take care of the rest
As for the glass top vs screened. I find it best to have 50 - 75% of the top covered with glass. It helps lock in humidity and still allow for ample ventilation.
I have an automatic mister and used it for several months, but have since removed it and now I hand mist all my tanks. I just felt like the auto mister was disconnecting me from a lot of the hands on time with the frogs and the tank. Was to easy to just feed them and not look back with the auto mister going.
They will love the 55G tank and all the space. They love to be up off the substrate so 21" hight is great for them.
The fogger is going to be great for helping to control the humidity. You could even look at connecting it to a ZooMed HydroTherm and let that turn the fogger on and off as needed to maintain proper humidity. As with any automatic fogger or mister. You want to make sure it isn't running so much it swamps out the substrate, but the false bottom will help you avoid that if you are checking it regularly. Are you going to install a way to access the False Bottom so you can siphon out excess water if needed?