Yes, instrument skills make you safer. They make you fly more accurately, whether in cloud or not, and entering cloud is no issue. Also Aerobatic skills and advanced handling courses make you safer.
In fact the FAA recognise that ALL further training make a pilot safer, which is why their training is geared towards encouraging further training - something which Europe sadly doesn't seem to recognise as can be seen from their philosophy towards national ratings etc....The UK, with the IMCr did recognise this, but now thanks to the United States Of Europe we shall see this valuable rating disappear in the near future......