Congrats on adopting Kingston, your Majestic Palm but my first question is about the millipedes in your houseplant soil. Did you use purchased potting soil? It is important not to use soil from your garden on indoor plants as this is a common way to introduce pests and outdoor soil does not drain as well as potting soil sold in plastic bags at garden centers. Try placing a cut potato near the base of the palm to attract the millipedes that will dig into potato. Then you can dispose of them easily. Leaves with brown tips are most likely suffering from dry air so mist the palm more often. Leaves with brown spots could have leaf spot disease caused by over watering or sudden chilling. Yellowing leaves most often because of underwatering. Brown leaves are natural if they are the oldest or lowest leaves on the palm and can be cut off but do not pull off or you will damage the main trunk. If the brown leaf is rotting at the base than that is a sign of too much water. A millipede feeds on decaying plant matter but it would not me leaving the dry spots on the foliage. Palms do not need to be repotted often and do better in smaller pots as too much soil can stay moist for a long time and lead to  root rot. Do not let pot sit in drainage water. Palms hate having wet feet. I suggest you water just enough to keep soil slightly moist so feel the soil before you water. This means in summer when days are longer the plant may need more water and less watering in the winter. I think you are doing a good job of palm parenting and you should enjoy many happy years together. Keep growing, Marianne Binetti