It's weird because I'm just as afraid of a black swan of unforeseen, runaway financial collapse due to pandemic countermeasures. People seem awfully glib about how many will die from the pursuant depression.
We had our chance to get this together years beforehand. We even had a chance to have lower impact interventions be effective 2-3 months ago.
There are no chances for light economic impacts now. Use lighter mitigation methods and productivity and demand will get hit by the illness and death itself, both the first order effects that hit those infected (which would be wider), and the second order effects as people improvise their own rightly fearful responses. The main difference you can count on is that the timing would move closer to the peak. AFAICT nobody has a clear model of whether it would be better or worse.
1. All evidence shows children have very low risk of severe illness. It can happen but is very very unlikely.
2. Immunity for corona viruses lasts months or years. Why should it be different for this one? Opposing news stories are mixtures of early discharges from hospitals and false negatives test results.
Studies that test also asymptotic cases from Italy and Heinsberg (Germany) (e.g. https://www.faz.net/aktuell/gesellschaft/gesundheit/coronavi...) indicate a R0 much higher than 2 or 3 (more between 5 and 10). We do not know infected people(!!!). We just know cases. My belief and hope is that virus is so infectious live can return to normal in weeks not months because almost everybody already has or had it (in areas with community spreading). Don't panic. Distance and wait.