Phoenix reborn, it sounds like the disease is festering away, and the downside of not using effective therapy is that scar tissue can be built, if it hasn't been built already. Damage, interfering with the absorption of nutrients, might not be reversible if not dealt with in time. With constant flares, it is doubtful you are ever truly in remission, if one defines remission as bringing Crohn's to a dead stop - no flares, no symptoms, no festering visible on a colonscopy or biopsy, no labs with high CRP or ESR, nada.
Surgery was suggested for my own daughter nearly four years ago. Her stricture was so tight that the doctor couldn't get into the TI with a scope. However, after treatment with diet and Entocort over the past years, the stricture vanished. If your own stricture, like my daughter's, is not made up mainly (or at all) of scar tissue, then surgery might be premature. I realize it's a tough call, and share your concern about side effects of 6 mp and Imuran. But consider surgery, by no means risk-free, a last resort.
Entocort might be worth considering - often, it is taken along with 6mp. You could try starting Entocort at the highest dose, 9 mg, and then decide after a month or so whether to introduce 6 mp.
If considering 6mp, then a TPMT test should be done. My daughter's GI tested her for the TPMT gene, which is really annoying, because you can have the gene but still have low TPMT activity, putting you at risk for serious side effects.
http://www.labtestsonline.org/understanding/analytes/tpmt/test.html