I had my reversal in January after having my colon removed in June of '09. The surgeon said my rectum looked good, so he left it. Once healed, I had the reversal and have had no control issues, and only occasional "butt burn." I'm not diabetic, so can't help you there, but I do avoid too much sugar as it can be gas-producing, plus I can't have it as I've had gastric bypass and can no longer tolerate too much sugar.
I've never been a big vegetable fan, but I'm able to eat anything I want. I do avoid raw and/or gassy vegetables (broccoli, cauliflower, most beans) and don't eat lettuce as I don't digest them very well. And I haven't had any carbonation since my colectomy as I didn't want the extra gas in the bag, and have continued to avoid it since my reversal. My surgeon said I could eat anything I want. I found what worked for me with the ileostomy works for me now, and I can even eat more as I'm not worried about
emptying a bag and have bowel control. I've never had any control problems since my reversal. Another plus has been that I can sleep through the night again. I never really got a good night's sleep with the ileostomy as I had to get up to empty the bag during the night (well, sometimes it decided to empty itself, too!).
I do take an occasional immodium or, for me, eating more protein can help to thicken things up. You'll just have to experiment to find out what works for you.
I've had no regrets!