COVID-19 is the name of the disease, which stands for coronavirus infectious disase 2019 (year it was discovered). The specific virus is called SARS-CoV-2, it belongs to the coronavirus classification which includes SARS and MERS
The short is that the government needs to do everything in its power to avoid straining the healthcare system to the point of collapse.
In short, yes. Look up the "hammer and the dance" strategy for disease mitigation
We do not know. Our adaptive immune system functions by forming antibodies to diseases (particularly to bacteria and viruses). There were early studies in a Chinese monkey species I came across that did at least show an immediate immunity to the disease. However, reinfection is still plausible and viruses tend to mutate (hence seasonal flu every year)
You should check out the CDC's website on COVID19. From what I remember off the top of my head, half are completely asymptomatic but capable of shedding the disease. The remainder mild cases have nonspecific flu-like symptoms. More concerning symptoms to watch for that can be specific to the disease are fever, headache, nonproductive or "dry" cough, shortness of breath. Unfortunately, there is a lot of overlap in symptoms between COVID19 and run of the mill respiratory viruses.
That's a very hard question to answer since the disease is so new and there are multiple clinical trials running all over the world. We will probably have a more definitive answer in the next 2-3 months. Currently, we are using hydroxychloroquine and azithromycin to shorten disease length but there is still limited data on this. There is consideration that remdesivir, an antiviral used for Ebola, may be efficacious. Newer studies are now looking at tocilizumab, an medication used for severe arthrities since it targets inflammatory markers known to cause "storming" which results in respiratory collapse. Other antivirals commonly used to suppress HIV are being studied as well with mixed results. This is a rapidly evolving area of study so it will require frequent checks.
Great question. People are stupid and everyone has an opinion.