Max Shutter speed
Panasonic GM1 can shoot continuously at max speed of
5 fps and has max shutter speed of
1/500 sec. GM1 also has an electronic shutter which can shoot silently at max speed of
1/16000s. One thing to keep in mind is that electronic shutter may cause rolling shutter / jello effects, and also banding issues under artificial light on your images.
Flash
Unfortunately GM1 doesn't have an external flash shoe so you are limited with the built-in flash.
Focusing
Panasonic GM1 features a Contrast Detection autofocusing system. The AF system has 23 points to choose from.
Panasonic GM1 also features
Face detection AF where it intelligently detects the faces in the frame and locks the focus automatically.