The palm tree might be nothing to worry about as long as the green fronds at the top remain healthy, and they look very healthy in your picture. Palm fronds have a life span of 6 months to a year depending on the species, then the ones near the bottom naturally die and fall off as the tree gets taller. This is why they have x-shaped scars on their trunks. All of your plants look like they may need fertilizer mixed in with the water, though. The ficus is probably salvageable if you keep watering it regularly, those things are chosen as houseplants for their durability and bushes and tree tend to grow back easily, but picking off and throwing away the dead leaves would allow the plant to expend more energy on growing back new ones.

I don't think the cactus is suitable for your climate, though. I'm in a part of the US that has a minimum temperature of -5°F to 0°F and the only cacti that grow here are prickly pear, which definitely shouldn't be in a pot, and some species of barrel cactus. If you ever turn the heat off while you're away on holiday in the winter, and the minimum temperature is -10, the cactus won't be happy, in Arizona and Mexico a lot of them only do well up to zone 8 or 9. I don't know how hardy yours is, because I can't tell the exact species from the picture, but I've never seen tall, thin, ribbed cacti like that growing outdoors anywhere but the hot desert Southwest. If you live in a valley it could be even worse, a lot of places high up in the mountains will border on zone 5, even if the map doesn't specify for such small areas.

They definitely need a lot of heat and light as well, I have my barrel cactus and christmas cactus in a South-facing kitchen window in a climate that's as sunny as northern Spain's, and it still leans toward the light. Here is a map of average annual sunshine in Europe and the USA, it certainly doesn't look cactus friendly. They shouldn't be watered more than once per month either, the soil in your picture looks wet. Try putting it on a windowsill and leaving the blinds/curtains open. If none of your windows face South it might just not be possible for you to grow cactus, especially in a climate with less sun than Seattle.