What's your question? Ask

This is very common as they age. Just a tap can send them scattering. You can also try giving it just a little more light. This may help some, but this is the natural process of the plant.

This is likely a fungal infection. The most common cause is when the soil remains wet for too long. Make sure the soil dries out a little between watering.

The next time that you water, you can replace 1/4 of the water with peroxide. This will kill off any infection in the container. The old growth will not recover, but new growth will remain healthy. This article will help: https://www.gardeningknowhow.com/ornamental/cacti-succulents/burros-tail/burros-tail-care.htm

You should definitely keep these misted more often than you would typical plant. Another thing you could do that would help rooting, would be to mix a spoonful of honey, and a crushed aspirin tab up in warm water, then spray the soil with it. This will improve your rooting.

It sounds like you are over watering your plant. Over watering will lead to root rot and the mushy succulent leaves are a sign of this.

This article will refresh you on the care of your plant.
https://www.gardeningknowhow.com/ornamental/cacti-succulents/burros-tail/burros-tail-care.htm

Cacti and succulents are usually very resistant to dry air and so are some epiphytic plants. Some plants resist dry air by producing leaves with fewer stomata than normal, thus reducing water loss. Many have abandoned leaves altogether and breathe through their green stems.

It appears to be Burro's Tail. They do not grow upwards, so staking will not be necessary. They are a trialing plant. It appears to be needing just a little more light as well. Leaves should be tightly packed, with very little room between them.

This article will help you to care for these: https://www.gardeningknowhow.com/ornamental/cacti-succulents/burros-tail/burros-tail-care.htm