What are Phalaenopsis growth habits?

[Judi]

I have been growing phals for a few years now, but I'm not sure how they grow after a few years. I grow mine in pots, some are quite tall with 10 leaves or more. They flower regularly, but they are starting to be too tall--and top heavy for the large leafed phals--for the pots. I suppose in the wild they would just be supported by the tree they grow on, but I don't have that option in my home. Would phals just keep growing under normal conditions or do they stop at some point ? I'm afraid some of them might break near the top. I also have an other question about a smaller phal I saved. The roots started rotting so I had to severely prune the roots and repot. The phal is doing well now with new roots and is flowering, but it also has roots growing mostly above the lower two leaves which is also where the spike is. Should I replant it again deeper in the pot with these roots in the medium? I read that the roots growing above the potting medium are air roots and would rot if potted, is this true? Why is my phal doing this ? I am attaching picures and would appreciate any info. you might have.