Hi,
I think that you will find more that one condition under the title type 3, some people have linked this name to Alzheimers , others have called Type 1 with insulin resistance type 3. (though thats more often termed double diabetes)
However, the 'official WHO definitiion includes types 1,2 and a third category called 'other' types This category includes diabetes resulting from specific genetic conditions or genetic defects, surgery, drugs, malnutrition, infections, and other illnesses and is sometimes referred to as type 3 diabetes.
As to the problems resulting from a total pancreatomy, I did find some research papers by googling pancreatomy AND diabetes. The main difficulty arises from the lack of glucagon in addition to the lack of insulin so requiring very careful monitoring to avoid serious hypos. It really is a specialised field and I don't know of anyone in similar circumstances. Hopefully you will have some good guidance from an experienced endocrinologist. Perhaps also you might be able to find some help from the Diabetes UK (ie the Charity) careline.