I’ve heard this idea about lifting an orchid by the leaves a couple times now. I totally disagree with that idea. No matter what you plant a phal in, if you lift it by the leaves, it will pull out of the pot. You can do that with cattleyas potted with rhizome clips because the clip will hold the plant in the pot. I don’t suggest doing that with phals..
The clear slotted pots with the raised center that you’re talking about are excellent pots for phalaenopsis. One of the biggest favors you can do for your plant is to use the smallest pot size that the roots will comfortably fit in. I use 3”, 4” and 5” clear plastic pots for most of my phals.
Back when I used sphagnum I would put it in the pot fairly loosely but with no big air spaces. Since you’re using clear pots you can take a bamboo skewer or the blunt end of an orchid stake and push the sphagnum down around the roots while you look through the side of the pot to see where it needs to go. In the book ‘Moth Orchids’ the author says that some people pack sphagnum loosely and some tightly but that the author liked it in between the two. Kind of medium packed.