Most that know(and I am considering myself one of those for this moment) will say your better of with lots of clean power over your speakers rated "wattage" than too little. If you start overdriving 804's I would imagine the woofers would start bottoming out, and you would hear that. If you are playing the music you say you are, I would have a hard time believing you could do any damage. The speaker can handle huge amounts of power on transients and such, its just sustained volume and abuse, bass control(if you have one) cranked all the way up, distortion being obvious and not doing anything about it.
Personally it sounds as if you have a nice set up, i would think the Classe and the B&W is good sound.
Personally it sounds as if you have a nice set up, i would think the Classe and the B&W is good sound.