Referring to the two subquestions of 1.2 as 1.2.a and 1.2.b, a more logical order of considering the subproblems of 1.1 and 1.2 is the sequence 1.1.a, 1.2.a, 1.1.b, 1.1.c, 1.2.b.
In 1.8.a, you may assume that the two convex hulls are separated by a vertical line.