Judging from how the plant looks, I would water it more often, or soak it for a while when you water. I live in a dray climate and add sphagnum moss to my Phals (about 1/3 of the potting mix) to hold water a little longer. I tend to underwater and they still get thirsty sometimes.
What I see of the roots looks good. Water enough to keep them fat... your pot looks dry in the pictures and the funny looking bottom leaf does look like an older leaf that is ready to give up. Your plant should probably hold the older leaves better as it adjusts to your care (and your care adjusts to the plant). Leaning is fine, most of my Phals choose to lean no matter what I do to them! Imagine a big old monster that has 16 leaves, each leaf over a foot long that grows flat sideways in its pot! I think I have a picture... Its a couple of leaves bigger now and has gnarly roots all over. I finally found a larger pot for it and will repot soon, as it just finished blooming two spikes for me! I keep it in heavy pots so it won't fall over. BTW, I soak it every so often in the sink (hardly fits anymore) and then wipe down the leaves and dry them to clean off dust and be sure it doesn't rot.