Hi thanks for the compliment.
Answers to your questions below.
1 - I like the rear speakers and the Dipole. Don't really think it was necessary considering I have 9 speakers + 2 subs in that room. The sides do a great job - but I went with the same brand as the fronts and they recommended these Dipole. They sound great and I'm happy with them.
2 - My previous theater was 16:9 and I knew I wanted 2.34 from that point forward. It really depends on what you will be using the theater for. If you watch a lot of Movies - especially new, then 2.34 may be the way to go. If you plan on watching HD TV, or lots of HD Streaming and gaming, then 16:9 might suit you. For me, I primarily watch HD movies and I use XBMC as my media manager/player. With XBMC, it has the capability to fit a 16:9 into 2.34 and it does a pretty good job of it ... so I have little to no issue. You can also watch a smaller version of 16:9 to fit the screen. I've done it a few times and the non-masking didn't bother me. No regrets and I would build this aspect again for myself over 16:9.