[chispamed]

For the second point, take a look at these studies:

Ferretti et al. (2020). Quantifying dynamics of SARS-CoV-2 transmission suggests that epidemic control and avoidance is feasible through instantaneous digital contact tracing. Science. https://science.sciencemag.org/content/early/2020/04/09/scie...

Ganyani, Tapiwa, et al. "Estimating the generation interval for COVID-19 based on symptom onset data." medRxiv (2020). https://www.medrxiv.org/content/10.1101/2020.03.05.20031815v...

The first study also touches on the point of transmission through surfaces which they argue should be at the very most 10% of all cases but probably less and a German virologist who's one of the leading experts in coronaviruses, Prof. Dr. Drosten, said that he and many others believe that surface transmission is almost negligible: https://www.ndr.de/nachrichten/info/coronaskript162.pdf (in German).