Only reason Ninetales may not be in S is due to it's typing inferiority to Politoed. Otherwise, it would be S for sure.
Whether or not it is suspect, I don't know. There are some pretty good checks to sun out there, since most sun teams follow a standard formula anyway (trapper+sweep); as for rain, there are just too many possibilities. AND rain strips Genesect off it's 4x fire weakness - like that thing needs any more support.