...I have a very long torso (six-foot-two, but only a 30-inch inseam) and my back is killing me, even with bar risers...
Holy crap...were you a wrestler in high school?
I've got a 31 inch inseam and just support off the balls of my feet.
I think instead of bar risers, you need stock or lowers...you must have a VERY upright riding position (unless you have T-rex arms) which may be one reason your back hurts.
Actually, I wear a 36-inch sleeve and until I blew out my rotator cuffs, was a competitive weightlifter (I am proof of interbreeding between Neanderthals and Homo Sapiens). Reaching the ground is no problem, thanks to my clownishly large (14) feet (insert your own penis joke here). If I lowered my bars, I'd be staring straight down at my front wheel. I figure I can't get the bars any higher without swapping cables and hoses. I otherwise love this bike, but it's not a very good fit. Let's not even discuss helmets. I wear an 8.