I would up the percentage of bark. It is more effective than the pumice for aeration as well as providing some moisture retention.

FWIW, I use the 5-1-1 mix for all my containerized plants, indoors and out, with the exception of cacti or succulents. And that formulation relies on 5 parts bark fines (or suitably sized orchid bark) to one part each of peat/coir and pumice/perlite.

If drying the soil fails to get rid of the fungus gnats, you can reduce the population of fungus gnats by watering once with 1 part 3% hydrogen peroxide and 4 parts water. As noted, be careful not to wet the leaves with it, it can burn them.

https://www.gardeningchannel.com/how-to-get-rid-of-fungus-gnats/

Repeat when they get bad again, if they do.

I've no feel for tropical clime indoor soils; here in PA, I actually use simple Miracle-Gro Moisture Control for most things that aren't succulents or borderline desert plants. They need it as my current indoor humidity is 31%. :-)

I would omit the worm castings. In outdoor organic gardens it is a valuable ingredient, but indoors in pots where you are using synthetic fertilizer regularly, it doesn't really add anything. And, it is expensive. On the other hand, it certainly isn't going to hurt anything.

I too would not use worm castings.

Fungus gnats nibble at root material as larvae, so...yeah. :-)

A little OM is not necessarily a bad idea. I use it myself. It's certainly easier to apply in liquid form--dissolved fish emulsion, liquid kelp, or liquid blood meal (very diluted), but there's nothing wrong with applying it in solid form either. It does work in via bacterial and fungal decay and watering over time, but overdoing it can lead to some mess and smell, the primary reasons why it's not recommended.

However, bacterial and fungal decay (the same bacteria and fungi, point in fact) are required to decay the liquid forms, and bacteria (many of the same species) are also required to reduce liquid urea to usable nitrogen (urea is only incidentally usable in small amounts directly).

Liquid organics are simply easier to use and less likely to smell, being sent directly into the soil and applied, generally, quite diluted. The fact that sometimes I've seen app recommendations so diluted as to be practically useless can be discussed at another time. :-)

Let's just say that anything can be over- or under-done, and blanket claims that things absolutely do or do not work under any circumstance are, at best, circumspect. Bacteria and fungi are ubiquitous.

Worm castings are mostly an issue just because they're not all that significant in terms of food, but they're an amazing source of biological activity if stored correctly. That's useful if you have a soil you know to be quite sterile and that has major problems. Most soils simply don't. But I'll never object to using small amounts in any mix--a pinch will do, and a good, active pinch is a good thing.

But as a food source? Not really, they're 1-0-0. So, roughly 1% nitrogen by weight, or not very much. And less than 1% phosphorus and 1% potassium. That's not good. You can get far better plant food far cheaper far easier. Just pick up the right food for the plant, it'll be cheap. Even a huge bag of urea (46-0-0) runs about $25 for fifty pounds. Pounds.

And most soils are OK on potassium and phosphorus anyway, at least to start out.