Is it possible to reveal the Gnome3 launcher by just moving the mouse to the left hand side of the screen? Sometimes I just want to quickly flick my mouse to the left to reveal the launcher, but instead I have to go up to Activities and then down to the launcher.
Did you try flicking the pointer to the very upper left corner of your screen? That's how it works in Debian, at least.
No, you can't. The "Activities Overview" only can be activated using the upper left corner of the screen or clicking in the "Activities" label in the same quadrant. I think you could get this behavior with extensions but isn't in my knowledge anything like this.