Answer from cs61c-el (David Tung 16479725) for Question 1
If everything is represented as data, then that means that everything can be altered.  Therefore, I could potentially write a program that could change the instructions that I am passing to the computer, simply by loading new values into the memory where I have instructions.  This could be prevented by perhaps declaring certain segments of memory "read-only," but to do this through hardware would limit the size of programs that could be written, or we would be forced to use other hardware, which would complicate hardware design.