Went to Benitses was back in 1981/82 it was ok then but not having been in Corfu before did'nt know any better it did get rather rough but I believe that in the last few years they have got a new mayor who has really made the place very nice, as we have friends that live nearby in Kinopeasti a Greek village in Perarma he is Greek she is English and they say it's now a very nice place to go to, a new mariner has been built your not too far from Corfu town which is beautiful, and you can get a local bus to take you to most places on the Island.
Yes September can be rain althought we went both times in September and encountered the odd day, but believe October is the real rainy season.
Have a great time.
pojo