In general, the speakers can range from 6ft-10ft, center to center. Going wide may create an overly diffuse sound that don't provide a good center fill. Narrower would hinder the sound stage overall and the ability to place across. There isn't a minimum from a side wall, but ideally one would want 3ft from the center to side wall to delay the first reflection arrival to listener. This allows the our hearing to discern the direct radiation from the reflection and maintain them as two events. Adding absorption or diffusion will reduce the reflection amplitude, which you mentioned you have some form of such.
Revel speakers have a way of producing a even handed, neutral, and relaxed sound that is engaging while still providing good dynamics, bath macro and micro. They don't have the immediacy that some speakers provide, but I find their balance much more enjoyable over a wider range of genres than most I've listened to. You simply stop listening to speakers and enjoy the music.