FWIW, I think this is a useful idea. But I think it would be more helpful if you clearly explained why you choose those stats and rethought what you are trying to say. I personally care about "When can I feel safe going out?" Testing is just a means to that end.

* I would lead with the % of the population tested (not the total) and make it in the last 7 days, since I really care how likely they are to detect a current outbreak.

* I think to be really useful, it needs to be localized by county, since what I really care about is how likely I am to get infected, and that means I are about testing in my area.

* I would go with the positive rate in the last 7 days. It's important to explain that a high positive rate indicates they are probably only testing people with symptoms, and so they are probably missing lots of infectious asymptomatic cases.

* Then, I think I would drop the recent growth rate in testing, because I suspect that the growth rate is not going to grow consistently, and also that testing growth will be unevenly distributed. I am skeptical that it is meaningful to try to predict when testing will achieve specific milestones.