1)
What is the significance of after 12 months?
1.
Malbim: Initially he feared the dream and did not go outside; he was humble in front of Hashem. When he saw that a year passed and evil did not come upon him, he thought that the decree was nullified. Only then, he went to the royal palace.
2)
What is the meaning of "Mehalech Havah"?
1.
Rashi: He was walking.
