Phillips and Pozidrive are designed to rise out of the screw with excess torque, Japanese JIS shouldn't lift out till a higher torque. If I remember correctly!
Yes. essentially the end is flattened not pointy like a Phillips. And the JIS screw heads also flatten out and American Phillips will not sit properly
Many of us switch out the engine machine screws on old gold wings to Allen/hex. BUT BE CAREFUL you can get easily over-tighten and strip them out
