The object of the preposition "of"

For example, a skyscraper in a large city is a significantly more complex object than a modest family dwelling in a small town, but the underlying principles of construction and design, including questions of mechanics, energy and information distribution, the sizes of electrical outlets, water faucets, telephones, laptops, doors, etc., all remain approximately the same independent of the size of the building.

1.
In the above sentence, is it

1. including questions of (mechanics, energy and information distribution, the sizes of ~~~)

or

2. including (questions of mechanics), (energy and information distribution), (the sizes of ~)

??

2. Also, is it

1. (the sizes of electrical outlets), (water faucets), (telephones), (laptops), (doors) ~

or

2. the sizes of (electrical outlets, water faucets, telephones, laptops, doors)

??

Which one is right? And why?