I would suggest that you go by the guides linked above, but as a general rule you're going to want the speakers to be separated by the approximate distance that you are sitting from the speakers. So, in your case 9 feet apart will be preferable to 7. I would suggest you toe them in so they're on-axis as well. Off-axis the treble will roll off, and the Dentons are already rolled off in the upper frequencies.
Due to being rear ported, it is best to get the Dentons out away from the rear wall. Bass will be boomy if they are too close. Mine are about 16" away from the wall, and I would go no closer. I don't think the wall mounts would be a good idea unless they were extended out considerably from the wall.
Some others mentioned that the Dentons aren't their best at low volume levels. I've found that they require clean power and damping to be dynamic at all volume levels. They aren't the easiest speakers to drive with 86dB efficiency and low impedance. I moved from an EL34 PP amp to 50-80 WPC SS amps, and wasn't satisfied until I moved up from there to an NAD C 370 (120 WPC) power section. Now they are dynamic at all volume levels. IMO, since these speakers are voiced for warmth, it is best to pair them with an amp that has neutral tone.
This is just my $.02 based on my use of the Dentons of course. In the end, you should do what sounds best to you.