Hi there,
well ... I was a heavy smoker for 18 years (age 18 until 36) and got UC when I was 25. When I was diagnosed, I was still a smoker. So it wasn't like that UC broke out when I quit smoking. However, everytime I tried to quit smoking, I had flares within weeks of non-smoking and I started smoking again and again.
Now I am a non-smoker since 2 1/2 years and yes, my flares are more frequent and more severe. I never had to take Prednisone for flares before; now my flares last 4 months as a non-smoker. I admit that I am really tempted sometimes to take up smoking again just to get rid of the flares, but smoking didn't really help me against the UC anymore in my last years as a smoker. That's the reason I gave up (and of course, the obvious health risks of smoking and the costs etc.). By the way, i don't think that the nicotine is the factor that is "beneficial" with UC, it is more the carbon monoxide of cigarette smoking. I tried the patches - they did nothing (for the UC). Only cigarette smoking has helped me, but like I said, even smoking doesn't help me anymore and that's why I stay quit. Besides I had the hardest time quitting and don't want to ever go through the withdrawal and all that jazz before.
I hope you will have success in whatever you decide to do. PERSONALLY, I don't think that smoking will do the trick in the long run, because you will run into other health problems to add on top of UC.