"The more toe in used the the [sic] smaller the soundstage." In fact, it depends upon the speaker and the room. A speaker like your WP 6 requires toe-in due to beaming caused in the upper mids by the use of what is basically a woofer as a midrange cone. Some speakers can achieve best staging when the axis crosses several feet in front of the listener (Revel Salons in some set-ups), others tend to sound best with no toe-in (Thiels), etc.
"Speakers should be on the long wall and 10 to 12 ft apart min." D'Appolito'd speakers like Dunlavys can play best that way, but many speakers will have a weak or non-existent center image if run without toe-in. As for long wall versus short wall, long wall happens to be my preference with most speakers, but not always.
"Seating should be no more than the distance apart, preferrably a ltlle [sic] less." Many speakers are best listened to far-field, particularly those with drivers spaced far apart so that the sound coming off the drivers has the space needed to properly integrate. The room boundaries and room treatment also affect optimal listening distance.
"Sit low with back against treated wall if possible." It depends. A basic rule of listening room acoustics is that either the front wall or back wall should be treated, but not both (and not always the back wall). Also, some speakers (the Aerial 20-T) require space behind the listener.
If you are interested, Robert Harley's book about hi-fi basics covers a lot of these points. Also, I noticed that your system is all-digital and uses Krell electronics - do you have experience with other types of systems?