well I have two suggestions for you.
1. Get an engine guard or highway bars and put some pegs on it so you can change your sitting position from time to time.
2. Can also get a sheepskin seatpad from Alaskaleather.com. I have one on my Interstate. Click the photo below to see a larger image and you can see the sheepskin pad on my seat. Sitting on sheepskin allows your rear to get some air. Sitting on leather causes boils, If you don't believe me ask a cowboy.
When I ride I only have my feet on the floorboards long enough to get me up to speed, then their on the pegs and I kick back, leanup against my backrest and cruise. With the heal/tow shifter, I can just take my left foot off the peg and and either step on the front for down shifting or on the back for upshifting (It's like spurring a horse). With my right foot on the peg I just slide it down a bit and use my heal to tap the rear break as needed for flashing the breaklights or slowing down. The heal/toe shifter rocks. Once you get one, you'll never be without again. Having to upshift with your toe changes the whole ergonomics of the ride.
My brother has it down so well he never even has to take his left foot off the peg, he can upshift and downshift the front toe shifter just by using the heal of his left foot. He can catch the bottom of the toe shifter with the heal of his foot for upshifting. It just takes practice and soon your muscle memory will do it without even thinking.