Well, thanks Ovidius, but, no offense, you don't really answer my question.
I'm asking if hooking pfnMessageBegin and other message functions (assuming I only do checks there, and execute code if needed to) can, in a situation say where multiple players shoot at the same time, it can lead to damage not taken into account i.e. If it can affects regs.
So yeah... I just want to know if messages are used for providing data necessary to damage calculations by the server.
Is this technique (i.e. using Orpheu this way) differs much from AMXX's register_event() hook?