Best advice would be to start over, lol, jk..
Good luck, I am not super familiar with a lot of what you bought, I like denon avr's, but I think your speaker and sub choice could have gotten you more for much less money...
a couple more notes,
why a cd and bluray player?
why the expensive media player, you can buy a media pc and do much more with it...
I think you are complicating something that can be much more simple, I haven't heard stmos yet, but from what I hear from the people who have, its not great. HT is one of those things you can complicate to destruction, I tried 7.1 before and quickly realised 5. is better, so why go 7 for an outcome that isnt as good...
We all have our preferences though, welcome to AH, as far as setup goes, buy your cables at mono price and follow the manuals as well as you can, try to place your sub well too, because that little guy is going to need all the help he can get...