First of all, I wish you all the best in yur nrusing aspirations and career.. We need more diabetics entering the health professions. The most experienced endos and nurses have no idea what it is like to be a Type 1 diabetic - as a young child, a teenager, a yound adult, or a 48-year middle-aged diabetic such as I. Have at it and enjoy what you can contribute.
I don't have any references to send you to on the questions you psoe, and they are great ones. Types i diabetes is very fickle - in my case, no one before me in my families and neither of our two children (at 40 and 35) or our granddaughter (at 10 months) have shown any indciation of the disease. It is a mystery and often in my estimation the results of chance - a vulnerable gene subjected to the right virus or bacteria, and you've got it. On the other hand, there is a lot of evidence of genetic likelihoods although I don't believe that they are as devloped as they should be - after all knowledge of the disease dates back to the Egytpians several centuries B.C. Not nearly enough funds and effort are being expended.
There are some sources like Joslin Clinic in Boston, Mayo Clinic, Johns Hopkins, and others which you can search. There is also a lot of stuff available through the ADA and JDRF. Today, the web is full of stuff, but it doesn't seem to answer the ultimate question - How, Why, and Who? Type 2 is a lot more within an indiviual's control as I am sure you KNow.
I wish you good luck in your search. If you find things of interest, please share them with us. The collegial nature of these forums is great, and we need, each of us, to use it more effectively.
My experience and good fortune with our children (and that is in spite of my wife's family having a history of some form (apparently Type 2), none of our offspring show any signs.