Well...when I got diabetes I lost weight and never got to the amount I should have. My brother weighs almost 100 pounds more then me even though he is only an inch and a half taller.
Trust me diabetes can led to: High blood pressure, Kidney failure, heart attacks and loss of limbs(feet). I've already suffered some.
If you want to put weight on eat carbs with no sugar such as pasta.
Firstly, I am not trying to argue, its really hard to explain things in a place where "tone of voice" doesn't count.
I never said I wanted diabetes, a lot of my family suffer from both type 1 and type 2 diabetes, and it doesn't look fun. But if it was guaranteed to put weight on (I can not emphasize the "guaranteed" enough) then I'd probably (again, emphasis on the "probably") consider it. As it sits being underweight (I should weight between 55-60kgs and weigh approximately 37 atm, bmi = 13) leaves me at risk of everything you mentioned minus limb loss, as well other organ failures plus weak bones etc. As for your diet plan, I've tried it and it doesn't work. My body seems to refuse to store fat, and as you'd know, you kind of need fat to create muscle. In the last 6 years I've seen 4 different dieticians, more drs than I can count, countless therapists (in case it was psychological, I never got that), radiologists, pathologists etc and none of it helped. They don't know what's wrong with me, or how to fix it. So I just have to keep experimenting until hopefully something works. Who knows, maybe the next dietician might actually come up with something that works!