well right off the bat i can see that your bone_hand_R is is in bone_arm_L, so perhaps you have parented it wrong?
i cant really tell what its doing without textures, as i have only done things for reforged, so what exactly is happening for you?
i guess its just a name in the end really for the bone, i did notice the left hand was wonky during your attack work swim animation, it should look normal now, im looking at white texture here so i dont know, the rest of the animations seem fine, try and find out i guess