> Everything points to this thing having a mortality similar to the seasonal flu.

Can you justify this? I want to be convinced, because at the moment I think it's very optimistic. (There are different estimates for seasonal flu mortality, but it seems to be around 0.1%, so I'm assuming that's roughly the number you mean.)

The mortality measured in China is about 2%. Outside of China, I read it was rather 0.15%. And what I read is the 2% is based on the number of people who show up at the hospital with symptoms and get diagnosed. The doctors think there is a large but unknown population out there, with milder symptoms, who don't show up. Understandly. If you have what looks like a cold, you don't really want to go to the place where everyone is contaminated with the coronavirus.

So it looks like 2% is kind of the upper bound but that the actual rate will be lower.

This is wrong. The only way to get 0.15 is by dividing dead over total cases - which is not the correct math since most people infected are still ongoing.

You have to divide dead over dead+recovered, and outside of China those numbers are still too small to get a reliable number.

In China it is 2% outside Wuhan, but inside Wuhan it is over 4% since the medical system has broken down.

Similar being at least 100x more lethal?

The problem is that the mortality rate might seem lower than it actually is as it takes time for people to die after the infection is identified. Comparing the number of peopl infected upto today and number of deaths upto today is not a correct comparison. A two week delay in the stats should give you a better idea of the mortality rate.

One more pandemic like the flu to contend with is also not a good idea.