Remember that there is only one authorized Coronavirus testing facility in Russia, and it's far from Moscow (in Novosibirsk).
Not true. It used to be that way in the beginning, but now the tests are widespread.
Obviously there is a healthy level of mistrust towards the government, but I don't think anyone is hiding real numbers. It's impossible to hide overrun hospitals and hundreds of deaths.
Overall, I think the government response has been adequate. They closed the border with China back in January. They have been screening flights from China, Italy, France, Spain, etc + screening flights from Moscow to some other Russian regions. Plus, quarantining everyone coming from these countries, or anyone with a fever. Without a doubt, the response to this threat has been very serious.
It's worth noting that Russia has more hospital beds per capita than any major country other than Japan and South Korea. Moscow alone (pop. 12.7m) has more ventilators than Italy. Additionally, the city is building two temporary hospitals for COVID-19 patients. Though it's not going to be enough if there is an epidemic.
I'm highly critical of Putin and the Russian government, but I suspect - when the stakes are high - they are very competent. If they were hapless idiots, they wouldn't have survived 20 years in power. Moscow mayor, in particular, has been excellent throughout this whole ordeal.
edit:
https://edition.cnn.com/2020/03/21/europe/putin-coronavirus-russia-intl/index.html
Moscow health officials denied the accusation and said they were testing pneumonia patients for coronavirus. The WHO's Dr. Vujnovic also was skeptical about Vasilyeva's claim.
"If there was a hidden, unrecognized burden somewhere it would be seen in these [pneumonia] reports," she said. "So I do not believe this is happening, which does not say that you might not see an increase of cases in the next period, because we have seen that in many countries."