It should be noted that Snorri Sturluson was a product of the early medieval scholarly system. His writing and translations were influenced by not only early Christianity (thus Adam and Eve and references to the misunderstandings of the pre Christian people) but also by the trend of referencing classical history in their writings (thus the references to Troy). He sanitises much of his writing and though still 'bawdy' in places does not usually contain the blatant sexual or lude referrals found in the Poetic Edda 'written' by an earlier unknown source. In the Prose Edda we see a much more direct representation of certain events...and a less rowdy and lude translation of the 'poems'. (See the Lokasenna and the story of Thor meeting with Odin in disguise on the ferry crossing).
Thor was often considered during Snorri's time as the Primary God as opposed to Odin (and the various 'tribes' or cultures had various intrepretations of their beliefs with many considering Thor as the Chief God). However though the initial comments can be confusing, Odin is still seen as All Father and the primary godhead. It should be understood that names are repeated and Odin, though the brother of Bor initially in the Prose Edda is also considered the son of Bor and one of his names.
The giants are not conceived necessarily like the modern conception of giants being beings of great stature. Yes, some were, such as Ymir, but others were of normal stature and many of them wise and moreso the women were desireable and of great beauty.
An open mind and a tongue in cheek reading of the Prose Edda can see through the veneer of early Christianisation and into the true heart of the myths and 'pagan' beliefs of the early Norse. Remembering that Iceland was settled in around 800 AD, one gets an idea of the late Christianisation of the Norse cultures and a better understanding of the invaders of various earlier Christianised lands.