1) No, I would say this is not correct. My theater setup is in one corner of a larger 8,000 cu ft room. I have 4 Qs8's and they work perfect. The purpose of the surround speaker is to wrap or envelope you in the experience. For a direct radiating speaker this experience only comes for the person in the sweet spot. With the Q's, everyone is in the sweet spot.
Your room is not unusual, and actually more common.
2) No matter what speakers you use, your going to hear them throughout the house, direct or not. Again, the purpose of the surround channels is to envelope you in the sound, not be to a pinpoint location. In theaters, the walls are "lined" with many direct radiating speakers, the Q's simulate these many speakers in one package.
3) I don't have a problem with 4 Qs8's, but some people will go with Q's for the "side" surrounds, and use direct radiating for the "back" surrounds because they say they are better for muli channel music listening. Personally, I think the Q's do great for both music and movies.
4) It is best if the top/bottom driver have at least 4+ inches to breath a little. Maybe if you provide a drawing/picture of your situation we can give you options. The Q's are very forgiving on placement, because they "do" wrap you in the sound, so they are not as picky on placement. They don't have to be symetric with each other. They can be wall or ceiling mounted with the right bracket...
