Does that mean any core functionality for OpenGL 2 and higher should be accessed by glXGetProcAddress() (Yet its defined in gl.h/glext.h)?
3.4. The libraries must export all OpenGL 1.2, GLU 1.3, GLX 1.3, and ARB_multitexture entry points statically.
It's possible (but unlikely) that additional ARB or vendor extensions will be mandated before the ABI is finalized. Applications should not expect to link statically against any entry points not specified here.
Also should I explicitly load anything with glXGetProcAddress() if all the prototypes are actually defined in glext.h? I am not talking about checks for extention support but about linking.