Even if the virus were to be isolated, what does it mean?

It means that information that it doesn't exist at all is disinformation. I think such provably false "information" is intended to make those looking into it look bad, make them look like "conspiracy theorists" as this guy looks like. It gives the people pushing a false narrative fuel to discredit those who say negative things about the narrative.

What constitutes a case?

There are symptoms that have been discussed that match previous SARS cases. This virus seems to attack a certain type of cell that expresses the ACE 2 protein (notably specific cardiopulmonary cells), and I think cells in the nose and throat as well (I'd have to look that up).

People have been tested when not even being sick. Why?

The type of test used (PCR) is being used fraudulently (too many cycles). The test itself is already only useful in certain situations, but for a test of this type it is almost useless even in the best of cases. But much worse than that, the protocol that was pushed by the WHO (at nearly twice as many cycles as standard PCR) was guaranteed to produce many, many false positives.

Using the test in this manner can only be for one reason: to falsely get the numbers up, to push fear through the population, to force draconian responses, and to make the population subservient to their fear and those political and health department leaders that were "trying to help them". There is no other logical reason they would have used the PCR test in such an obviously incorrect manner, and every single research biologist in the world who has ever done PCR knows it, which is basically all of them.

Is it even contagious?

I think it may be very contagious. I think it was modified to be very contagious. I haven't looked into its actual biology as much as I should have. I have been concerned with other aspects of it. Once I realized it was not very deadly these types of effects became less of a concern for me.

Does it mean it's virulent enough to lock down the world

Most definitely not. Its a bad cold. Before we had good therapeutics it may have been a problem, but just vitamin D and zinc are likely sufficient to prevent serious harm in all but those who were very ill before encountering the virus. HCQ and zinc do seem to be excellent if taken even in those with comorbidities if taken before serious damage is done.

wear cloth masks, use excessive sanitization techniques, socially distance

Wearing cloth masks is useless to prevent the spread of the virus. Wearing masks of any type without constantly replacing them with sterile ones does more harm than good. Constant sanitation reduces the strength of our immune system, making us more likely to get seriously ill or die if we do encounter the virus (or any infection). Socially distancing may or may not help stop the spread, but we don't actually want to stop the spread. THEY want to stop the spread so they can keep us living in fear longer.

We live in fear because they are programming us, and for no other reason. I believe that SARS-cov-2 is a real virus, and I believe it gets people sick. I believe it has killed some people, but almost all of them were sick with other things first (cancer, diabetes, etc.). The evidence also suggests that HCQ and zinc, maybe an antibiotic as therapeutics, if you do get sick, are likely enough to prevent serious damage from this virus (if done before it gets bad). Not one other thing seems to be necessary.

All evidence I have seen, doing probably thousands of hours of research suggests the worlds overreaction to SARS-cov-2 is a scam designed to take us into their "Great Reset" aka the NWO.