Question

Can a morbidly obese person die of starvation?

Answer 1

cannot tell if you are serious or not, but let me pretend you are.
Yes, adipose tissue(fat cells) will not sustain a morbidly obese person forever. Plus one factor you did not include was if they had access to water. :p

Answer 2

Yes

Answer 3

yes, you need glucose for the brain and the body only stores enough for a few days. The mechanisms for compensating for having no glucose intake involving the buning of fat but are not ideal and cause damage in other ways (become acidotic etc)