Re your #20. Thanks for the link.
What it seems to be saying is there are a number of tests that may be given but their reliability are open to question and they do not give a complete or even relatively foolproof picture. The tests are changing constantly not only because the virus seem to be mutating, but also newer and more definitive tests are evolving. Plus, costs of testing can be a factor in testing suspect cases.
In other words, diagnosis is still a crapshoot.