Whilst there are no special qual's required to receive a RIS, the criteria for calling 'conflicting' traffic is vastly different between RIS and FIS. An a/c is in receipt of a RIS and is advised of traffic as it is going through a patchy area of Wx/Cloud, the then more worried than normal GA dude/dudess, then shakily asks for an update. Dutiful ATC then offer a RAS to try and provide that warm and fuzzy feeling. Unsure GA dude/dudess accepts thinking this is a good idea. Vectors then take him into IMC/IFR. Very unfuzzy feeling all round, no?