...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 **** Sapiens). Reaching the ground is no problem, thanks to my clownishly large (14) feet (insert your own ***** 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.