Matt,

I have all of the above. In fact, I've gone totally separates with the Spektrum DX7 and the AR6100 Rx.
I didn't try the stock t. motor with the Bl m. motor, but I would say that you would need the DD to compensate for the extra power. I have not cut the remaining part of the stock t. motor mount off, (yet), and I don't have a problem balancing. I did not shorten the boom.
Flight times will, of course, depend upon the mah of the lipo. I safely get 12 mins. with a TP910 mah lipo, I could probably go a little more. I actually fly two 6 min flights. I fly the e-flite 800 mah lipo for two 5 min flights.

orlbuzz