Hi triplejtm,
According to other posts from QS8/QS4 owners, drywall anchors will indeed support the QS surrounds. JohnK's placement advice is excellent. The QS8s are supposed to direct their sound the way you describe it--"going off at angles with the rear hitting the wall and the front going into the rest of the room"--when they are located to each side of the listening area. What the QS8s do is simulate what occurs in a large Dolby Cinema, where four or more surround speakers line each side wall. Because of the big cinema space the delay times are longer and produce a sense of envelopment for most of the audience.
In home environments, delay tiimes are relatively short, so your receiver/processor adds digital delay to the surround signals so you hear them after the sound from the front and center channels (sound travels about 1 foot per millisecond--a thousandth of a second). The QS8's multidirectional drivers create a rich mix of reflected sounds that simulate what occurs in a cinema (and in real life!). You will also receive some direct sound that travels from the QS8 tweeters; it is these that provide the directional cues for sounds that are hard-mixed to the left or right surrounds.
Experiment a bit with the height of the QS8s before you drill screw holes. Usually 2 feet or more above ear level (when you are seated) is advantageous. Have someone hold them temporarily or use a couple of stepladders to support them while you listen. It's not that critical, but some tweaking of the QS8s height and location is always worthwhile.
Regards,
