That's kind of an odd question, why do you ask?

And what's life like in Christchurch, New Zealand?

Each of these health problems can have different degrees. So, it really is hard to say.

I think diabetes is the worse. Second worse asthma and celiac the least worse. Asthma and celiac are more treatable but with diabetis I mean the bad one you can end up with an amputated leg..

I don’t know.. Breathing is one of my favorite pass-times, but I ‘m sure if you ask somebody that suffers from diabetes they will tell you that diabetes is worse. Same goes for the other ones you mentioned. If you have first hand experience on a condition your answer will reflect that.
I guess everybody would like to be a prime example of health. Uh, except my aunt. She would like to have all three. In the worst degree.
I hate hypocondriacs.

If I had border line diabetes, I would pick diabetes but it really depends on the level..

Celiac requires a diet as does diabetes but it is more severe and i hate being restricted.

I'd rather have celiac disease. I do have celiac disease. It's the easiest to manage, requires no further medical attention, no drugs, no follow up testing and is one of the few diseases where the patient alone is in charge of the outcome. Asthma can be life threatening and requires medication and sometimes medical intervention to treat it. Diabetes is partially under the control of the patient, but often requires medications and lots of follow up testing. If you are a giant insurance conglomerate, it doesn't matter. All three will put you in the uninsurable category.