Michael:I did not read the book. But I did see the movie and it is trash. Remember, once Hollywood gets a book and then writes a screenplay, they usually ruin the story. On the other hand if the movie followed the book closely, then it was a crappy book. Have you seen the movie? If not don't bother.   I have seen the movie.  I ...

Did you read the book?

If it were me, I would go:   2.0  (towers) 2.1  (add sub) 3.1 (add center) 5.1 (add surrounds) 7.1 (add back surrounds) 7.2 (second sub)   etc...   That's the order I would build a system from scratch, personally.  

Looking for some opinions here. In my previous setup, I had my sub located between the left channel and the TV stand, nicely spread out.  With my current place, I don't have the luxury of that because of the TV stand I'm using and the wall size. Here's a pic from when I first set everything up: I picked up two Rythmik F15's, ...

Shifting things around like in your design could work well.  I'd still only go 5.1 in that case, though.  Just my opinion.

Does the couch have to be facing that direction?  I would face the couch South which would allow for better placement of the surrounds.  Or just go 5.1.

1. The speakers have little rubber nubs that cover the threads.  You can thread from the back or the bottom.   2. You can use third party adapters if you'd prefer.   3.   Build a shelf   4. No    5.  Aperion speakers all sound pretty good mated with each other.  I wouldn't worry.

It doesn't have to be at ear level.  Just needs to be AIMED at ear level.  If you have to place the center channel in one extreme or the other (above or below), figure out a way to aim it at the listener's ears to achieve the best results.

What you're describing is fairly common...not everyone has the ability to have everything line up exactly right.  I would place the center above/below the TV, though...if the TV is off center, so should the center channel.   If you have a receiver with something like Audyssey on it, it can help compensate with weird ...

I think you'll see a noted improvement. As to your upgrade path, I'd say determine it based on your usage.  If HT primarily, go 5C then 5T.  If music, the opposite.   I'm also a proponent of external amps.  Made a world of difference in my system.