[HamletEagle]

Code looks good. Approved.

The only thing which should be changed is to move origin retrieval inside !PrimaryAttack check. A suggestion may be to make a file for resources, it's easy for the end user to change the models & sounds. Definitions for DMG_BULLET and DMG_ALWAYSGIB already exists in hlsdk_const, but it's okay to just copy them inside your plugin.
Also put cvar description inside source file, again, easy for the user to know what each cvar does.