The difference is when you draw by memory you won't remember every tiny detail, and you make/draw it in your own way vs. having the object in front of you you can copy it almost exactly.
Can you clarify the question?
a. 2
2 time
b. idk
c. the notes with the double lines
d. one
e. a barline is literally a vertical line that ends a measure
Bonus. You could put p (piano) f (forte) or mf, mp, ppp, fff, ff
