Actually yes. The virus that caused the 1918 "Spanish flu" is now one of the seasonal flu viruses that afflict us every year.
Possible. A pre-print paper from 3 weeks ago describes how the researchers already found a large deletion in populations in Singapore. The authors theorize that the virus is sacrificing strength in order to keep up the infection rate. The same deletion also occurred in SARS and MERS, effectively ending their runs.
It doesn't seem like there's much evolutionary pressure given both the estimated R0 and the asymptomatic transmission to make this disease learn to become less deadly. It transmits just fine despite killing people. I suppose our immune systems will just get better at learning about it (similar epitopes) as we continue to be exposed year after year.
Possibly, but it will take many years for this to happen.