select only download via Google Playstore, or accept anything from anwhere. It's ANDROID, remember, which lets the customer decide
Oh OSFO.
What you very carefully skirt around is the fact that its a double edged sword.
That extra flexibility comes with a great deal of risk, and to be honest, the vast majority of people will never have much use for non Google Playstore apps anyway !
You have to remember, its a smart phone, not a computer. The focus should be on stability and security of the platform.
There are also other issues with the Android platform such as issues with different platform version APIs.
As much as you might personally hate it OSFO, the Apple platform has a great deal going for it if you look at it on an impartial technical level.
Also remember OSFO, that if people want to be idiots and run random third party apps on their iPhone, they can always jail break them.