Screw or no screw? In my experience, if a device is designed to be used with a screw, most surgeons will use one. But yes, there are occasions when some surgeons will consider the shell is secure enough and doesn't need one.
As for options for special situations, there are many variations for different requirements in the femoral components of most devices, offset necks, longer/shorter posts, etc. But the shell, no. Liners might have a hooded feature if they want or need extra protection against dislocation but that's about it.