I recommend Microsoft's Launcher, it's simple and gets out of your way. Similarly, Edge's search widget just launches a browser and executes your search. This really should be the stock behaviour that Google should provide.
"... application stores are fast becoming the prime delivery mechanism for infected applications..."
I completely disagree with that statement. People downloading pirated or fake APKs from the web is the prime delivery mechanism for infected applications.
Regarding #1, it's a pain when the stats break, and I agree it needs to be more robust and accurate, but it has no effect on your rankings what so ever.
https://www.informit.com/store/latex-companion-parts-i-ii-97...