The choice is up to you. Cut it down if it goes brown etc. etc. There is an FAQ to read about cutting the spike or not plus plenty of old posts on this subject. Some Phals will rebloom off old spikes. Others will not. Depends on the ancestors. Picture what the result will look like if it blooms at the ends of the cascading spike and make a decision.

It's so late in the season, I would expect some leaf drop. Also those poor plants have probably been in pots sitting around at Lowes for many months and a few weeks for you. That in itself would cause some stress and more leaf drop. Unless the plants look like they're croaking completely, I doubt you have anything to worry about. Get them in the ground so they have some time to establish themselves before winter - assuming you are in a colder climate. You don't give any info about where you're at. Kevin

It sounds like over watering. You need a fast draining potting medium. When I water mine the water runs almost right through the soil and drains out. My jades get full sun in the summer and I only water them about every 4 to 6 weeks if they need it. My jades have been inside since October in low light and have not been watered since September and are doing great. I usually only water when the leaves begin to get soft. I then soak and leave to drain. The west window should be fine for light.

This is actually how large Aroids grow. Aerial roots grow in the crease between the oldest leaf and the stem. When the plant becomes taller (or longer, I should say) this will become more evident. The oldest, tiniest leaves naturally yellow and die, however I find this takes longer for M. Deliciosa (another large around, if you're familiar) than many of my other plants. If you are fertilizing, the white residue could be from that, or if you have hard water it may be from that too. Picture is a little unclear, but it doesn't look like mold to me. How did the roots look when you repotted? If they were brown or squishy, it could be rot caused by cold damage as suggested above. This is my monstera. You can see the aerial root is growing out of the stem just above a dried leaf that I cut off.