At some point we'll have unified memory and storage anyway. Our brains are already unified in our perception of memory, so I have no problem telling people the storage amount as "memory".
Our brains are not unified. Separating long and short memory makes a lot of sense.
I hope not! All that rubbish we put in RAM doesn't need permanently storing! That's why the distinction exists, plus writing to non-volatile permanent storage systems is slower. Much slower.
Yeah, the name of flash memory ruins the shorthand of "memory" meaning "volatile memory". As you point out, "storage" is still a good term for persistent memory.
This confusion has existed since the beginning of consumer PCs. Loads of people mix up RAM and HDD space (probably because they're the same units)