Q: I upgraded to iOS 10.0.2 and do not like it. Can I retrograde to the earlier version?

Go to settings then general then accessibility then scroll down to home button. You can change the home button to work like it used to.

You can't go back, but here's a workaround to your problem: to get to your sign in screen withouth pressing the home button just swipe right on only place on the screen.  You'll get a choice of 8 apps to open.  Choose any of them and you will get your sign-in screen.

That's strange.  That screen I referred to seems to be the screen with Widgets.  It seems you can edit which Widgets appear.  Mine was on by default, but I can't see how to turn this screen on if it doesn't appear.  Perhaps someone else can help.