There is certainly some very flowery writing in Chopin's correspondence with some of his male friends (the letters to Titus W.... are often cited in this respect). Of course, it was the style of the times.
George Sand certainly was bisexual; it shouldn't be difficult to find documentation. The Potocka letters (iirc, the "poem" is from there) are generally considered to be forgeries. My late teacher made a BBC documentary on them; sadly I think it's now deleted. When I mentioned the letters, and the forgery allegations, he said "well yes, but it's not as simple as that". Unfortunately I didn't get any more information, because the conversation moved on to gossip about d'Albert.
The good doctor appears to be something of an eccentric, obsessed by Elgar and blue panties, Britten and boys, how only a pervert could appreciate the Scriabin concerto, etc. Don't take my word for it, look around his website
